Assessing the impact of the COVID-19 pandemic on childhood vaccine uptake with administrative data

This study examines the impact of the COVID-19 pandemic on childhood vaccination coverage in New Zealand using population-wide administrative data. For each immunisation event from ages 6 weeks to 4 years, we compare vaccine uptake of children who became eligible for immunisation during the pandemic to earlier-born cohorts whose immunisations were due before the pandemic. We find that the initial phase of the pandemic had, on average, small or nil effects on timely immunisation at the four infancy events, but a large effect at the 4-year event of -15 percentage points. Nine months after eligibility, catch-up among the pandemic-affected cohorts was largely achieved for the infancy immunisations, but 4-year coverage remained 6 percentage points below pre-pandemic levels. Vaccine uptake at 4 years initially dropped most among children of European ethnicity and of non-beneficiary parents but catch-up quickly surpassed their Māori, Pacific, and beneficiary counterparts for whom sizeable gaps in coverage below pre-pandemic levels remained at the end of our observation period. The pandemic thus widened pre-existing inequalities in immunisation coverage.

Vaccine coverage among children born to immigrant parents in Norway, 2000-2020

BACKGROUND

The Norwegian Childhood Immunization Program maintains a high national coverage of 95-97% in the most recent years. Whether there are subgroups with lower uptake is less studied. This study examines pertussis and measles vaccination coverage among six immigrant groups in Norway. These vaccines are normally administered as part of different combination vaccines and their coverage rate indicate the national vaccination coverage against a range of additional infections.

METHODS

Data from the Norwegian National Population Register were linked at individual level with vaccination data from the Norwegian Immunisation Registry. The final sample consisted of 53,052 children born during 2000-2018 in Norway to parents who were born in Iraq, Lithuania, Pakistan, Poland, Somalia, or Vietnam. Vaccination coverage was measured at 2-years of age. Multivariate linear regression was utilized to estimate the relationship between vaccinations status, year of birth, gender, mother's length of residency in Norway, and area of residence.

RESULTS

At two years of age, the majority of the children were vaccinated. Coverage among the groups varied at, above, and below the national average for the two vaccines. For most of the years examined, children born by parents from Lithuania, Poland, and Somalia had lower coverage for the measles vaccine (range 81-84% in 2020) than the national level (97% in 2020). Children born by parents from the Eastern-European countries also had lower coverage than the national level for the pertussis vaccine (range 87-89% in 2020).

DISCUSSION

This study illustrates how subgroups with lower vaccination coverage may exists within a well-established vaccination program with high national coverages. Differences in coverage were found for both vaccines, but the differences were more pronounced for the measles vaccine. The high vaccination coverage in Norway provides indirect protection through herd immunity for unvaccinated individuals, however, the lower vaccination coverage in some immigrant groups is a concern.

The influence of health service interactions and local policies on vaccination decision-making in immigrant women: A multi-site Canadian qualitative study

OBJECTIVES

Research on immigrant and refugee vaccination uptake in Canada shows that immunization decisions vary by vaccine type, location, age and migration status. Despite their diversity, these studies often treat immigrant and refugee populations as a single group relative to other Canadians. In this comparative study, we explored how previous risk communication and immunization experiences influence immunization decisions by immigrant and refugee women from three communities across Canada.

METHODS

Participants included women from the Punjabi immigrant community located in Surrey and Abbotsford, British Columbia (n = 36), the Nigerian immigrant community located in Winnipeg, Manitoba (n = 43), and the Congolese refugee community in Edmonton, Alberta (n = 18). Using focus groups guided by focused ethnography methodology, we sought to understand immunization experiences in Canada and before arrival, and what information sources influenced the immunization decision-making process by the women in the three communities.

RESULTS

Participants had differing past experiences in Canada and before their arrival that influenced how they used information in their vaccination decisions. Clear vaccination communications and dialogue with Canadian health care providers increased trust in Canadian health care and the likelihood of vaccine uptake. By contrast, weak vaccine recommendations and antivaccination information in the community prompted participants to decline future vaccines.

CONCLUSION

Given our participants' different communication preferences and needs, we argue that a one-size-fits-all communication approach is inappropriate for immigrant and refugee populations. Instead, multi-pronged communication strategies are required to reach participants and respond to previous experiences and information that may lead to vaccination hesitancy.

Predicting the intention to receive the COVID-19 booster vaccine based on the health belief model

COVID-19 vaccine boosters are recommended because the protection provided by previous doses eventually decreases, posing a threat to immunity. Some people, however, remain hesitant or unwilling to get vaccinated. The present study sought to investigate factors associated with the intention to receive the COVID-19 booster vaccine based on (1) the constructs of the Health Belief Model, and (2) trust in healthcare workers and science. A sample of 165 adults with two doses of the COVID-19 vaccine were recruited using convenience sampling. Data was collected using an online survey from November 2021 to January 2022. The survey included questions about participants' socio-demographic details, health beliefs, trust, history of COVID-19 vaccination, and the intention to receive a third dose of the COVID-19 vaccine. Ordinal logistic regression analysis showed that higher perceived benefits, severity, and trust in healthcare workers, and lower perceived barriers predicted higher willingness to get a third dose of the vaccine whereas perceived susceptibility and trust in science did not. Understanding the factors and health beliefs that underlie vaccine hesitancy are vital when developing effective interventions with the aim of increasing uptake of COVID-19 booster vaccines.

Adverse events following immunisation: Prospective cohort study evaluating Australian children presenting to specialist immunisation clinics

OBJECTIVE

Prior experience of an adverse event following immunisation is a known barrier to vaccination. Limited Australian data evaluating adverse event recurrence among children exists to inform clinical decisions. We aimed to assess adverse event following immunisation recurrence among children with prior adverse events and to evaluate if family history increased adverse event risk.

METHODS

A prospective cohort study was conducted from March 3rd until August 18th, 2023. Children ≤ 16 years with prior adverse events following immunisation in themselves or family were recruited from specialist immunisation clinics at two quaternary paediatric hospitals. Adverse event outcomes were collected via surveys administered at presentation, three, and eight days post vaccination, and analysed by key characteristics and potential risk factors.

RESULTS

Forty three of forty nine (43/49, 87.8 %) children enrolled received further vaccines. Of those who completed the follow up surveys, 50.0 % (16/32) reported an adverse event. Recurrence of prior adverse events occurred for 23.3 % (10/43, 95 % CI: 11.8 % - 38.6 %) of the cohort. Two of twelve (2/12, 16.7 %) participants with prior serious adverse events who received further vaccines reported a serious adverse event recurrence. No post review serious adverse events were observed in children with prior non serious adverse events. Neurological conditions were a risk factor for prior (neurological condition 3/3 versus no neurological condition 2/40, p < 0.001) and post review (neurological condition 2/3 versus no neurological condition 0/28, p = 0.006) post vaccination seizures. Family history had no relationship to post review adverse events (family history 5/8 versus no family history 11/23, p = 0.685).

CONCLUSION

Revaccination is safe for the majority of children with a personal or family history of adverse event following immunisation.

An economic evaluation and incremental analysis of the cost effectiveness of three universal childhood varicella vaccination strategies for Ireland

BACKGROUND

The cost effectiveness of childhood varicella vaccination is uncertain, as evidenced by variation in national health policies. Within the European Economic Area (EEA), only 10 of 30 countries offer universally funded childhood varicella vaccination. This study estimates the cost effectiveness of universal childhood varicella vaccination for one EEA country (Ireland), highlighting the difference in cost effectiveness between alternative vaccination strategies.

METHODS

An age-structured dynamic transmission model, simulating varicella zoster virus transmission, was developed to analyse the impact of three vaccination strategies; one-dose at 12 months old, two-dose at 12 and 15 months old (short-interval), and two-dose at 12 months and five years old (long-interval). The analysis adopted an 80-year time horizon and considered payer and societal perspectives. Clinical effectiveness was based on cases of varicella and subsequently herpes zoster and post-herpetic neuralgia avoided, and outcomes were expressed in quality-adjusted life-years (QALYs). Costs were presented in 2022 Irish Euro and cost effectiveness was interpreted with reference to a willingness-to-pay threshold of €20,000 per QALY gained.

RESULTS

From the payer perspective, the incremental cost-effectiveness ratio (ICER) for a one-dose strategy, compared with no vaccination, was estimated at €8,712 per QALY gained. The ICER for the next least expensive strategy, two-dose long-interval, compared with one-dose, was estimated at €45,090 per QALY gained. From a societal perspective, all three strategies were cost-saving compared with no vaccination; the two-dose short-interval strategy dominated, yielding the largest cost savings and health benefits. Results were stable across a range of sensitivity and scenario analyses.

CONCLUSION

A one-dose strategy was highly cost effective from the payer perspective, driven by a reduction in hospitalisations. Two-dose strategies were cost saving from the societal perspective. These results should be considered alongside other factors such as acceptability of a new vaccine within the overall childhood immunisation schedule, programme objectives and budget impact.

Immunisation deferral practices surrounding congenital heart surgery

BACKGROUND

Perioperative immunisation administration surrounding congenital heart surgery is controversial. Delayed immunisation administration results in children being at risk of vaccine-preventable illnesses and is associated with failure to complete immunisation schedules. Among children with CHD, many of whom are medically fragile, vaccine-preventable illnesses can be devastating. Limited research shows perioperative immunisation may be safe and effective.

METHODS

We surveyed Pediatric Acute Care Cardiology Collaborative member centres and explored perioperative immunisation practices. We analysed responses using descriptive statistics.

RESULTS

Complete responses were submitted by 35/46 (76%) centres. Immunisations were deferred for any period prior to surgery by 23 (66%) centres and after surgery by 31 (89%) centres. Among those who deferred post-operative immunisation, 20 (65%) required deferral only for patients whose operations required cardiopulmonary bypass. Duration of deferral in the pre- and post-operative periods was variable. Many centres included exceptions to their policy for specific vaccine-preventable illnesses. Almost all (34, 97%) centres administer routine childhood immunisation to patients who remain admitted for prolonged periods.

CONCLUSIONS

Most centres defer routine childhood immunisation for some period before and after congenital heart surgery. Centre specific practices vary. Immunisation deferral confers risk to patients and may not be warranted in this population. Further research would be necessary to understand the immunologic impact of these practices.

Population-based cross-sectional study of factors influencing full vaccination status of children aged 12- 23 months in a rural district of the Upper East Region, Ghana

BACKGROUND

Achieving universal health coverage includes ensuring that children have access to vaccines that are of high quality, safe, efficacious, and affordable. The Immunisation Agenda 2030 aims to expand services to zero-dose and incompletely vaccinated children and reduce immunisation rate disparities as a contribution to vaccination equity. This study explored the factors influencing full vaccination status among children aged 12 - 23 months in a rural district of the Upper East Region of Ghana.

METHODS

A population-based cross-sectional study was conducted among carers of children aged 12 -23 months in the Kassena Nankana West district. A multistage sampling technique was used to select 360 carers. Information regarding the vaccination status of children was gathered through a combination of children's health record books and carers' recollections. Information on potential determinants was also systematically collected for analysis in Stata version 15.0.

RESULTS

The results showed that 76.9% (95% CI: 72.3 - 81.0) of children had full vaccinations per the national schedule. All children received at least one vaccination. A higher percentage of carers with incompletely vaccinated children reported that they had travelled with their children as the primary reason for missing certain vaccine doses. Full vaccination status was significantly associated with secondary (aOR = 2.60; 95% CI: 1.20-5.63) and tertiary (aOR = 3.98, 95% CI: 1.34-11.84) maternal educational level, being in a partnership relationship (aOR = 2.09, 95% CI: 1.03-4.25), and residing in close proximity to healthcare facilities (aOR = 0.41, 95% CI: 0.21-0.80).

CONCLUSIONS

Our study found that nearly one-quarter of children aged 12-23 months in the study setting are underserved with vaccination services for a variety of reasons. Effectively reaching these children will require strengthening health systems, including eliminating vaccine shortages, addressing the unique challenges faced by unmarried women with children aged 12-23 months, and improving accessibility to vaccination services.

The coverage of influenza vaccination and predictors of influenza non-vaccination in Danish cancer patients: A nationwide register-based cohort study

BACKGROUND

Influenza vaccination is recommended and provided free-of-charge to Danish citizens aged ≥65 years and to individuals with acquired immunodeficiency. We aimed to estimate influenza vaccination coverage and investigate predictors of influenza non-vaccination in Danish cancer patients.

METHODS

A nationwide cohort study of all Danish citizens aged ≥18 years with an incident cancer diagnosis between 2002 and 2017. Using national registries, we assessed information on influenza vaccination and potential predictors of influenza non-vaccination. We estimated adjusted prevalence ratios (aPR) of influenza non-vaccination for patients aged <65 years and ≥65 years.

RESULTS

We observed 269,863 patients during 840,876 influenza vaccination seasons. The influenza vaccination coverage was 14 % for cancer patients <65 years and 51 % for those ≥65 years. No influenza vaccination in the previous season was associated with non-vaccination in the current season (<65 years: aPR = 2.75, 95 %CI = 2.71-2.80; ≥65 years: aPR = 5.15, 95 %CI = 5.10-5.21). Haematological cancer patients receiving chemotherapy had lower vaccination prevalence compared with those not receiving chemotherapy.

CONCLUSIONS

The influenza vaccination coverage was low among cancer patients. Influenza non-vaccination in the previous season was the strongest predictor of not receiving influenza vaccination in the current season. Haematological cancer patients on current chemotherapy had lower vaccination prevalence than those not currently receiving chemotherapy.

Use of invitations and reminders are associated with higher levels of Herpes zoster (shingles) vaccination uptake. A cross-sectional survey of general practices in Wales, and ecological analysis of uptake data, 2022

In 2013, shingles vaccination was introduced in Wales as a routine immunisation programme for older adults. Invitation for this vaccination has historically been recommended but not mandated by vaccination policy. We surveyed general practices to investigate if invitations and reminders are associated with higher uptake of shingles vaccine. Using data from general practices, we calculated practice-level shingles vaccine uptake between 01/07/2021 and 31/06/2022 for registered patients aged 70-84 years. We distributed an online survey via email to all general practices in Wales on their use of vaccination invitations and reminders, method of invitations, and characteristics of their vaccination delivery. We used linear regression to calculate coefficients and 95 %CI to measure associations between invitations and vaccine uptake, adjusting for key demographics, with a multi-level component to account for similarities between general practices within the same health board. Survey response rate was 37 % (143/384). Median vaccine uptake for responding general practices was 57 % (IQR 50-68 %) compared to 58 % (IQR 48-68 %) nationally. General practices inviting all eligible patients (n = 95) had a 9 % (95 %CI 6-13 %) higher vaccination uptake compared to those inviting none or some (n = 48, p < 0.001). Of practices sending invitations, those who reminded all patients (n = 42) had a 6 % (95 %CI 1-11 %, p = 0.02) higher uptake compared to those that reminded none (n = 30). Practice size was associated with higher uptake, with small practices (n = 11, p = 0.02) having coverage 9 % (95 %CI 2-16 %) higher compared to the reference population (medium-sized practices, n = 78). General practices inviting and reminding all eligible patients for shingles vaccination have a higher uptake compared to those inviting and reminding only some or none. From September 2023, shingles vaccination policy in Wales has been updated to explicitly mandate effective universal call and recall mechanisms in general practices.

The cost of human papillomavirus vaccination delivery at the administrative and health facility levels in the Philippines

Background

The World Health Organization has recommended the inclusion of human papillomavirus (HPV) vaccines in national immunization programs to address the global problem of cervical cancer. In the Philippines, HPV vaccination was introduced in a phased approach in 2015. This study seeks to estimate the cost of delivery of the HPV vaccination program and its operational context in the Philippines.

Methods

This was a retrospective, cross-sectional micro-costing study focused on ongoing HPV vaccination delivery and its operational context across all levels of the health system. Using structured questionnaires and data collection from secondary sources, the weighted mean financial and economic costs and costs per dose at the national, subnational, and health facility levels were estimated.

Results

The weighted mean financial and economic costs per dose of the HPV vaccination program aggregated across all levels of the health system were $US3.72and $29.74, respectively. Activities contributing most significantly to costs were service delivery and vaccine collection or distribution and storage at the health facility and administrative levels, respectively. The opportunity costs for health worker and non-health worker time accounted for 77% of the economic cost per dose.

Conclusion

The total weighted mean financial and economic costs of HPV delivery are within range of those reported in other countries. Costing studies can help identify cost drivers with local operational context to help inform policymakers and program managers in budgeting and planning interventions to improve program implementation.

Vaccination against COVID-19 - risks and benefits in children

Countries in Europe and around the world have taken varying approaches to their policies on COVID-19 vaccination for children. The low risk of severe illness from COVID-19 means that even small risks from vaccination warrant careful consideration. Vaccination appears to result in a decreased risk of severe illness including the paediatric multi-system inflammatory syndrome known to be associated with COVID-19. These risks have already decreased significantly with the emergence of the Omicron variant and its subvariants, and due to widespread population immunity through previous infection. There is a relatively high risk of myocarditis following second doses of mRNA vaccines in adolescent males, although the general course of this condition appears mild.   Conclusion: COVID-19 vaccination only provides a transient reduction in transmission. Currently, insufficient evidence exists to determine the impact of vaccination on post-acute COVID syndromes in children, which are uncommon. What is Known: • Vaccines against COVID-19 have significantly reduced morbidity and mortality around the world. • Whilst countries have universally recommended vaccines for adults and continue to recommend them for vulnerable populations, there has been more variability in recommendations for children. What is New: • In the setting of near universal existing immunity from infection, the majority of the initial benefit in protecting against severe illness has been eroded. • The risks of myocarditis following mRNA vaccination for children is low, but an important consideration given the modest benefits.

Research progress on emulsion vaccine adjuvants

Vaccination is the most cost-effective method for preventing various infectious diseases. Compared with conventional vaccines, new-generation vaccines, especially recombinant protein or synthetic peptide vaccines, are safer but less immunogenic than crude inactivated microbial vaccines. The immunogenicity of these vaccines can be enhanced using suitable adjuvants. This is the main reason why adjuvants are of great importance in vaccine development. Several novel human emulsion-based vaccine adjuvants (MF59, AS03) have been approved for clinical use. This paper reviews the research progress on emulsion-based adjuvants and focuses on their mechanism of action. An outlook can be provided for the development of emulsion-based vaccine adjuvants.

Strengthening the WHO Regional Office for Africa (WHO AFRO) COVID-19 vaccination information system

This manuscript describes the process and impact of strengthening the WHO Regional Office for Africa (WHO AFRO)'s COVID-19 vaccination information system. This system plays a critical role in tracking vaccination coverage, guiding resource allocation and supporting vaccination campaign roll-out for countries in the African region. Recognising existing data management issues, including complex reporting prone to human error, compromised data quality and underutilisation of collected data, WHO AFRO introduced significant system improvements during the COVID-19 pandemic. These improvements include shifting from an Excel-based to an online Azure-based data collection system, automating data processing and validation, and expansion of collected data. These changes have led to improvements in data quality and quantity including a decrease in data non-validity, missingness, and record duplication, and expansion of data collection forms to include a greater number of data fields, offering a more comprehensive understanding of vaccination efforts. Finally, the creation of accessible information products-including an interactive public dashboard, a weekly data pack and a public monthly bulletin-has improved data use and reach to relevant partners. These resources provide crucial insights into the region's vaccination progress at national and subnational levels, thereby enabling data-driven decision-making to improve programme performance. Overall, the strengthening of the WHO AFRO COVID-19 vaccination information system can serve as a model for similar efforts in other WHO regions and contexts. The impact of system strengthening on data quality demonstrated here underscores the vital role of robust data collection, capacity building and management systems in achieving high-quality data on vaccine distribution and coverage. Continued investment in information systems is essential for effective and equitable public health efforts.

Impact of nirsevimab prophylaxis on paediatric respiratory syncytial virus (RSV)-related hospitalisations during the initial 2023/24 season in Luxembourg

After Luxembourg introduced nirsevimab immunisation against respiratory syncytial virus (RSV), estimated neonatal coverage was 84% (1,277 doses/1,524 births) in 2023. That year, paediatric RSV-related hospitalisations, especially concerning infants < 6 months old (n = 72) seemed to decrease compared to the same period in 2022 (n = 232). In 2023, hospitalised children's mean age increased (14.4 months vs 7.8 months in 2022; p < 0.001) and hospital-stay length decreased (3.2 days vs 5.1 days; p < 0.001). In infants < 6 months old, intensive-care unit admissions appeared to drop (n = 28 vs 9). This suggests that nirsevimab prophylaxis reduced severe RSV infections, particularly in infants < 6 months old, thereby alleviating healthcare strain.

Researching childhood vaccine hesitancy in the wake of COVID-19

The COVID-19 pandemic has had a seismic effect on public healthcare, vaccine production, and on society. However, the pandemic has also had a methodological impact on social researchers, including those seeking to better understand vaccine hesitancy in relation to childhood vaccines. In this short communication, we describe the challenging experience of recruiting and conducting qualitative interviews with UK healthcare professionals and vaccine hesitant parents in early 2022. We also explore the way in which the context of COVID influenced our data analysis. Finally, we make recommendations for how researchers, including those using qualitative or quantitative methods, might learn from our experiences, as the complex and delicate relationship between society and vaccines continues to evolve in the wake of the pandemic.

Impact of the COVID-19 pandemic on the coverage and timeliness of routine childhood vaccinations in the Gambia, 2015-2021

INTRODUCTION

The COVID-19 pandemic caused widespread morbidity and mortality and resulted in the biggest setback in routine vaccinations in three decades. Data on the impact of the pandemic on immunisation in Africa are limited, in part, due to low-quality routine or administrative data. This study examined coverage and timeliness of routine childhood immunisation during the pandemic in The Gambia, a country with an immunisation system considered robust.

METHODS

We obtained prospective birth cohort data of 57 286 children in over 300 communities in two health and demographic surveillance system sites, including data from the pre-pandemic period (January 2015-February 2020) and the three waves of the pandemic period (March 2020-December 2021). We determined monthly coverage and timeliness (early and delayed) of the birth dose of hepatitis B vaccine (HepB0) and the first dose of pentavalent vaccine (Penta1) during the different waves of the pandemic relative to the pre-pandemic period. We implemented a binomial interrupted time-series regression model.

RESULT

We observed no significant change in the coverage of HepB0 and Penta1 vaccinations from the pre-pandemic period up until the periods before the peaks of the first and second waves of the pandemic in 2020. However, there was an increase in HepB0 coverage before as well as after the peak of the third wave in 2021 compared with the pre-pandemic period (pre-third wave peak OR = 1.83, 95% CI 1.06 to 3.14; post-third wave period OR=2.20, 95% CI 1.23 to 3.92). There was some evidence that vaccination timeliness changed during specific periods of the pandemic. Early Penta1 vaccination decreased by 70% (OR=0.30, 95% CI 0.12 to 0.78) in the period before the second wave, and delayed HepB0 vaccination decreased by 47% (OR=0.53, 95% CI 0.29 to 0.97) after the peak of the third wave in 2021.

CONCLUSION

Despite the challenges of the COVID-19 pandemic, The Gambia's routine vaccination programme has defied the setbacks witnessed in other settings and remained resilient, with coverage increasing and timeliness improving during the second and third waves. These findings highlight the importance of having adequate surveillance systems to monitor the impact of large shocks to vaccination coverage and timeliness.

Pain management in infant immunisation: A cross-sectional survey of UK primary care nurses

BACKGROUND

Childhood immunisation is a critically important public health initiative. However, since most vaccines are administered by injection, it is associated with considerable pain and distress. Despite evidence demonstrating the efficacy of various pain management strategies, the frequency with which these are used during routine infant vaccinations in UK practice is unknown.

AIM

This study aimed to explore primary care practice nurses' (PNs) use of evidence-based pain management strategies during infant immunisation, as well as barriers to evidence-based practice.

METHODS

A questionnaire was developed and distributed to nurses throughout the UK via convenience sampling in paper and online formats. Questions assessed the frequency of pain management intervention use during infant immunisation and barriers to their use.

FINDINGS

A total of 255 questionnaire responses were received. Over 90% (n = 226) of respondents never used topical anaesthetics or sweet solutions during immunisations, while 41.9% advised breastfeeding occasionally (n = 103). Parent-/caregiver-led distraction was the most frequently used intervention, with most nurses using it occasionally (47.9%, n = 116) or often (30.6%, n = 74). Most practices had no immunisation pain management policy (81.1%, n = 184), and most PNs' previous training had not included pain management (86.9%, n = 186). Barriers to intervention use included lack of time, knowledge and resources. Excluding distraction, pain management strategies were infrequently or never used during infant immunisation. Key barriers to using evidence-based strategies were lack of time, knowledge and resources.

Analyzing an immunization resource website: User browsing trends

PURPOSE

Access to internet-based resources may help to improve population health awareness and literacy surrounding immunization related topics. The primary aim of this study was to evaluate and analyze trends for a single immunization resource website, the Melbourne Vaccine Education Centre (MVEC).

PRINCIPAL RESULTS

Over a four-year period from 2019 to 2022, the website had over 2 million visitors from 236 countries. Users were predominantly female, in the 25 to 44 year age bracket and accessed resources using a mobile device. There was significant interest in specific vaccine related topics, particularly during the COVID-19 pandemic, that corresponded with key vaccine related recommendations and updates from a national level. Usage patterns saw spikes in interest around topics including COVID-19 vaccine administration techniques and adverse events following immunization.

MAJOR CONCLUSIONS

Use of online platforms including websites such as MVEC may reflect trends and behaviors towards immunization related information. Analysis of usage patterns have provided user insights into key domains of interest including areas such as vaccine administration, policies and programs, vaccine safety and barriers to vaccine uptake.

COVID-19 vaccination implementation in 52 African countries: trajectory and implications for future pandemic preparedness

INTRODUCTION

To end the COVID-19 pandemic, the WHO set a goal in 2021 to fully vaccinate 70% of the global population by mid-2022. We projected the COVID-19 vaccination trajectory in 52 African countries and compared the projected to the 'actual' or 'observed' coverage as of December 2022. We also estimated the required vaccination speed needed to have attained the WHO 70% coverage target by December 2022.

METHODS

We obtained publicly available, country-reported daily COVID-19 vaccination data, covering the initial 9 months following the deployment of vaccines. We used a deterministic compartmental Susceptible-Exposed-Infectious-Recovered-type model and fit the model to the number of COVID-19 cases and vaccination coverage in each African country using a Markov chain Monte Carlo approach within a Bayesian framework.

FINDINGS

Only nine of the 52 African countries (Tunisia, Cabo Verde, Lesotho, Mozambique, Rwanda, Seychelles, Morocco, Botswana and Mauritius) were on track to achieve full COVID-19 vaccination coverage rates ranging from 72% to 97% by the end of December 2022, based on their progress after 9 months of vaccine deployment. Of the 52 countries, 26 (50%) achieved 'actual' or 'observed' vaccination coverage rates within ±10 percentage points of their projected vaccination coverage. Among the countries projected to achieve <30% by December 2022, nine of them (Chad, Niger, Nigeria, South Sudan, Tanzania, Somalia, Zambia, Sierra Leone and Côte d'Ivoire) achieved a higher observed coverage than the projected coverage, ranging from 12.3 percentage points in South Sudan to 35.7 percentage points above the projected coverage in Tanzania. Among the 52 countries, 83% (43 out of 52) needed to at least double their vaccination trajectory after 9 months of deployment to reach the 70% target by December 2022.

CONCLUSION

Our findings can guide countries in planning strategies for future global health emergencies and learning from each other, especially those that exceeded expectations and made significant progress towards the WHO's 2022 COVID-19 vaccination target despite projected poor coverage rates.

The history of pertussis: from an ancient scourge to a contemporary health burden

The present article offers a historical overview on pertussis (whooping cough) by analysing the ancient epidemic manifestations of the disease and the path towards the discovery of an effective vaccine against it. The original mentions of pertussis are examined with reference to Mediaeval Afghanistan and the famous AD 1578 Paris epidemic described by the French physician Guillaume de Baillou. The historical data are then matched with information derived from analyses of phylogenetic trees of B. pertussis. Finally, this article also highlights some recent challenges posed to public health by this infectious disease.

Trends in childhood immunisation amongst Muslim children of Punjab (India): An empirical study

India's immunisation programme is one of the largest in the world and achieved great success over the years, however, some significant gaps are still observable in terms of achieving universal immunisation of children. Religion has emerged as a strong correlate for immunisation rates at national, state and global level. It has been observed that the rate of immunisation among children from Muslim families is comparatively less at global as well as at national level. Therefore, the paper attempts to understand immunisation trends among Muslims children from the north-western Indian state of Punjab. Based on the cross-sectional study of 400 households from district Sangrur of Punjab, results of the study show that rate of full immunisation among children from Muslim families was 88 per cent and none of the children were non-immunised. Reasons stated for partial immunisation of children included distrust of the government and belief that it would cause infertility amongst children. The present study reveals that religion per se does not appear to be influence rates of full immunisation. Geographical location, embeddedness of the community in the larger political and social milieu of their area, reach and acceptance of health workers at grassroots level emerge as strong factors contributing to higher rates of immunisation amongst Muslim children of Malerkotla.

Analysis of global routine immunisation coverage shows disruption and stagnation during the first two-years of the COVID-19 pandemic with tentative recovery in 2022

Whilst it is now widely recognised that routine immunisation (RI) was disrupted by the COVID-19 pandemic in 2020, and further so in 2021, the extent of continued interruptions in 2022 and/or rebounds to previous trends remains unclear. We modelled country-specific RI trends using validated estimates of national coverage from the World Health Organisation and United Nation Children's Fund for 182 countries (accounting for > 97% of children globally), to project expected diphtheria, tetanus, and pertussis-containing vaccine first-dose (DTP1), third-dose (DTP3) and measles-containing vaccine first-dose (MCV1) coverage for 2020-2022 based on pre-pandemic trends (from 2000 to 2019). We provide further evidence of peak pandemic immunisation disruption in 2021, followed by tentative recovery in 2022. We report a 3.4% (95 %CI: [2.5%; 4.4%]) decline in global DTP3 coverage in 2021 compared to 2000-2019 trends, from an expected 89.8% to reported 86.4%. This coverage gap reduced to a 2.7% (95 %CI: [1.8%; 3.6%]) decline in 2022, with reported coverage rising to 87.2%. Similar results were seen for DTP1 and MCV1. Whilst partial rebounds are encouraging, global coverage decline translates to a 17-year setback in RI to 2005 levels, and the majority of countries retain coverage at or lower than pre-pandemic levels. The Americas, Africa, and Asia were the most impacted regions; and low- and middle-income countries the most affected income groups. The number of annual Zero Dose (ZD) children - indicating those receiving no immunisations - increased from 12.1 million (M) globally in 2019 to a peak of 16.7 M in 2021, then reduced to 13.1 M in 2022. Overall, we estimate an excess of 8.8 M ZD children cumulatively in 2020-2022 compared to pre-pandemic levels. This work can be used as an objective baseline to inform future interventions to prioritise and target interventions, and facilitate catch-up of growing populations of under- and un-immunised children.

Direct long-acting antibodies: updating the language of RSV prevention to reflect the evolution of mAbs

Introduction

The language of medicine is constantly evolving, typically to better describe a new understanding of disease, adjust to changing social sensibilities, or simply to reflect a new drug class or category. We address the need for an updated language around monoclonal antibodies, or "mAbs" - a widely used medical term, but one which is now too general to accurately reflect the range of mAb pharmaceuticals, their effects, and the intended patients.

Methods

The question of "what should we call a monoclonal antibody immunisation against respiratory syncytial virus (RSV) to ensure accurate understanding of the product?" was the basis for a virtual advisory panel in May 2022. The panel was convened by Sanofi with the intention of reviewing appropriate language in terminology in the context of mAb-based prophylaxis for RSV. The panel comprised several global experts on RSV and vaccination, a trained linguist specialising in doctor-patient interactions and medical language, and several experts in marketing and communications.

Results

We suggest the term "Direct Long-acting Antibody" (DLA) for a specific sub-class of mAbs for use in prevention of RSV disease in infants. This terminology should differentiate from other mAbs, which are generally not used as therapies in infants.

Discussion and Conclusions

This change will more accurately convey the specific mode of action of a mAb in infants, and how it could impact the prevention of communicable diseases: this class of mAbs is not an active treatment, but rather will offer direct and rapid protection lasting at least 5 months.

Using new cold chain technologies to extend the vaccine cold chain in India: Equipment performance, acceptability, systems fit, and costs

This study evaluated the performance, acceptability, costs, and systems fit of three new cold chain devices in India: a second-generation ice-lined refrigerator (ILR), a solar direct drive (SDD) refrigerator, and a long-term passive device (LTPD). The evaluation was conducted over 15 months during 2016-2017. Sites were selected for their diversity in climate, terrain, and grid electrical supply, and 31 cold chain devices were deployed, 1 to each site. Results showed that all three technologies maintained correct temperatures. The SDD refrigerators had no malfunctions, whilst the ILRs had at least one malfunction, mostly due to the printed circuit board's sensitivity to the erratic power supply. The LTPD temperature display panel caused challenges initially that required replacement of all solar panels with lithium batteries. Yet the devices' long holdovers helped ensure vaccine potency. One challenge, particularly with the ILRs and SDD refrigerators, was condensation. The passively cooled LTPD was valued in settings with smaller populations and unreliable or no power; however, some its features, including the need to condition ice blocks, made it challenging to operate. In addition, the acceptable temperature range for the LTPD, as for all passively cooled devices (greater than 0 °C and less than + 10 °C), was confusing for some health workers due to the decades-long emphasis on maintaining temperatures at + 2 °C to + 8 °C. The greatest system-related benefit was establishment of new cold chain points (CCPs) at locations with intermittent or no grid electricity, bringing immunisation services closer to hard-to-reach areas. A key limitation of all three devices was the inability to freeze ice packs, which are required for vaccine carriers, somewhat restricting the potential of these technologies to reach underserved populations. Moreover, establishing new CCPs added costs to the health system. Results from this study, including costing data, can help guide decision-making.

Dimensions of equality in uptake of COVID-19 vaccination in Wales, UK: A multivariable linked data population analysis

Vaccination has proven to be effective at preventing severe outcomes of COVID-19 infection, and uptake in the population has been high in Wales. However, there is a risk that high-level vaccination coverage statistics may mask hidden inequalities in under-served populations, many of whom may be at increased risk of severe outcomes of COVID-19 infection. The study population included 1,436,229 individuals aged 18 years and over, alive and residence in Wales as at 31st July 2022, and excluded immunosuppressed or care home residents. We compared people who had received one or more vaccinations to those with no vaccination using linked data from nine datasets within the Secure Anonymised Information Linkage (SAIL) databank. Multivariable analysis was undertaken to determine the impact of a range of sociodemographic characteristics on vaccination uptake, including ethnicity, country of birth, severe mental illness, homelessness and substance use. We found that overall uptake of first dose of COVID-19 vaccination was high in Wales (92.1 %), with the highest among those aged 80 years and over and females. Those aged under 40 years, household composition (aOR 0.38 95 %CI 0.35-0.41 for 10+ size household compared to two adult household) and being born outside the UK (aOR 0.44 95 %CI 0.43-0.46) had the strongest negative associations with vaccination uptake. This was followed by a history of substance misuse (aOR 0.45 95 %CI 0.44-0.46). Despite high-level population coverage in Wales, significant inequalities remain across several underserved groups. Factors associated with vaccination uptake should not be considered in isolation, to avoid drawing incorrect conclusions. Ensuring equitable access to vaccination is essential to protecting under-served groups from COVID-19 and further work needs to be done to address these gaps in coverage, with focus on tailored vaccination pathways and advocacy, using trusted partners and communities.

RTS,S/AS01 malaria vaccine pilot implementation in western Kenya: a qualitative longitudinal study to understand immunisation barriers and optimise uptake

BACKGROUND

Malaria is a significant public health threat in sub-Saharan Africa, particularly among children. The RTS,S/AS01 malaria vaccine reduces the risk and severity of malaria in children. RTS,S/AS01 was piloted in three African countries, Ghana, Kenya and Malawi, to assess safety, feasibility and cost-effectiveness in real-world settings. A qualitative longitudinal study was conducted as part of the feasibility assessment. This analysis explores RTS,S/AS01 vaccination barriers and identifies potential motivators among caregivers in three sub-counties in western Kenya.

METHODS

A cohort of 63 caregivers with a malaria vaccine eligible child was interviewed at three time points over 24 months. A sub-set of 11 caregivers whose eligible children were either partially or non-vaccinated were selected for this sub-analysis. The 5A Taxonomy for root causes of under-vaccination was used to organise the inductively-coded data into categories (awareness, acceptance, access, affordability, and activation) and identify the factors influencing uptake across caregivers. A trajectory analysis was conducted to understand changes in factors over time within each caregiver experience. Caregiver narratives are used to illustrate how the factors influencing uptake were interrelated and changed over time.

RESULTS

Lack of awareness, previous negative experiences with routine childhood immunisations and the burden of getting to the health facility contributed to caregivers initially delaying uptake of the vaccine. Over time concerns about vaccine side effects diminished and anticipated vaccination benefits strongly motivated caregivers to vaccinate their children. Persistent health system barriers (e.g., healthcare provider strikes, vaccine stockouts, negative provider attitudes) meant some children missed the first-dose eligibility window by aging-out.

CONCLUSIONS

Caregivers in this study believed the RTS,S/AS01 to be effective and were motivated to have their children vaccinated. Despite these positive perceptions of the malaria vaccine, uptake was substantially hindered by persistent health system constraints. Negative provider attitudes emerged as a powerful deterrent to attending immunisation services and hampered uptake of the vaccine. Strategies that focus on improving interpersonal communication skills among healthcare providers are needed.

Ethnic inequities in routine childhood vaccinations in England 2006-2021: an observational cohort study using electronic health records

Background

Population groups that are underserved by England's childhood vaccination programme must be identified to address the country's declining vaccination coverage. We examined routine childhood vaccination coverage in England by maternal ethnicity between 2006 and 2021.

Methods

We created first, second and fifth birthday cohorts using mother-child linked electronic health records from the Clinical Practice Research Datalink (CPRD) Aurum. After validation against the UK Health Security Agency (UKHSA) and National Health Service England (NHSE) annual statistical reports, we described vaccination coverage for each vaccine by ethnicity and year. We used modified Poisson regression to analyse the effect of ethnicity on receiving the primary and full course of each vaccine.

Findings

Up to 1,170,804 children born after 1 April 2006 were included in the first birthday cohort, reducing to 645,492 by the fifth birthday. Children were followed up until 31 March 2021 at the latest. Children born to mothers in 9 minority ethnic groups and those of unknown ethnicity had lower vaccination coverage (61.3-97.5%) than the White British group (79.9-97.8%) for all vaccines. Indian, Pakistani, Bangladeshi, Chinese, Any other Asian background, and White and Asian ethnic groups had similar vaccination coverage to the White British group (above 90% for most vaccines in most years). Inequities particularly affected the Caribbean group (e.g. 61% coverage for the 6/5/4-in-1 full course in 2020-21 by children's fifth birthday; RR 0.66, 95% CI 0.6-0.74 compared with the White British group) and Any other Black, African and Caribbean background (e.g. coverage 68% for the MMR primary course in 2020-21; RR 0.71, 95% CI 0.64-0.78). These inequities widened over the study period. For example, the absolute difference in coverage between the Caribbean and White British groups for the full course of MMR increased from 12% in 2011-12 to 22% in 2019-20. These inequities remained even after accounting for sociodemographic, maternal and birth related factors, and also widened from primary course to full course.

Interpretation

Our findings suggest that urgent policy action is needed to address the ethnic inequities throughout England's routine childhood vaccination programme, which have been worsening over time.

Funding

University of Oxford Clarendon Fund, St Cross College and Nuffield Department of Population Health.

Resilience in childhood vaccination: analysing delivery system responses to shocks in Lebanon

INTRODUCTION

Despite rapidly growing academic and policy interest in health system resilience, the empirical literature on this topic remains small and focused on macrolevel effects arising from single shocks. To better understand health system responses to multiple shocks, we conducted an in-depth case study using qualitative system dynamics. We focused on routine childhood vaccination delivery in Lebanon in the context of at least three shocks overlapping to varying degrees in space and time: large-scale refugee arrivals from neighbouring Syria; COVID-19; and an economic crisis.

METHODS

Semistructured interviews were performed with 38 stakeholders working at different levels in the system. Interview transcripts were analysed using purposive text analysis to generate individual stakeholder causal loop diagrams (CLDs) mapping out relationships between system variables contributing to changes in coverage for routine antigens over time. These were then combined using a stepwise process to produce an aggregated CLD. The aggregated CLD was validated using a reserve set of interview transcripts.

RESULTS

Various system responses to shocks were identified, including demand promotion measures such as scaling-up community engagement activities and policy changes to reduce the cost of vaccination to service users, and supply side responses including donor funding mobilisation, diversification of service delivery models and cold chain strengthening. Some systemic changes were introduced-particularly in response to refugee arrivals-including task-shifting to nurse-led vaccine administration. Potentially transformative change was seen in the integration of private sector clinics to support vaccination delivery and depended on both demand side and supply side changes. Some resilience-promoting measures introduced following earlier shocks paradoxically increased vulnerability to later ones.

CONCLUSION

Flexibility in financing and human resource allocation appear key for system resilience regardless of the shock. System dynamics offers a promising method for ex ante modelling of ostensibly resilience-strengthening interventions under different shock scenarios, to identify-and safeguard against-unintended consequences.

Exploring factors that influence vaccination uptake for children with refugee backgrounds: An interpretive description study of primary healthcare providers' perspectives

BACKGROUND

Children with refugee backgrounds are at high risk of acquiring vaccine preventable diseases (VPDs) due to a complex set of factors, one being under-immunisation. In Aotearoa New Zealand (NZ), reported age-appropriate vaccination rates are suboptimal among children with refugee backgrounds.

METHODS

A qualitative interpretive description study was undertaken to explore factors associated with access and uptake of immunisations and develop strategies to improve age-appropriate vaccinations among refugee children post-resettlement in NZ. Semi-structured interviews were conducted with healthcare providers (nurses and doctors) (N = 14) across seven resettlement locations in NZ. Collected data was transcribed verbatim and thematically analysed.

RESULTS

Five themes were derived from the data that demonstrate the interrelated factors that influence vaccination uptake across the refugee caregiver, health provider and system levels. Providers discussed how caregivers' competing resettlement priorities and challenges early in the resettlement phase influenced their knowledge and access of vaccines and health services in NZ. Providers' knowledge of refugee caregivers' concerns was seen as a driver for positive change in forming therapeutic relationships with, and delivering health services to, former refugees. They discussed system level factors that influence access to and provision of immunisation services, such as resourcing, resettlement policies, system inefficiencies and missed opportunities. Emphasis was placed on communication between patients and providers to facilitate positive immunisation experiences. Overwhelming, providers displayed high motivation to improve immunisation services. Strategies were suggested to overcome identified barriers and included the provision of culturally and linguistically appropriate resources, education campaigns, reducing access barriers (e.g., after-hours clinics), and improving system efficiencies.

CONCLUSIONS

These findings highlight root factors that impact immunisation uptake and experiences among children with refugee backgrounds. To reduce the burden of VPDs, broad system level changes are required to address the barriers to vaccine uptake faced by both families of refugee backgrounds and health providers.

Acceptance of COVID-19 vaccination and vaccine confidence levels in Thailand: A cross-sectional study

BACKGROUND

Vaccination is considered effective for minimising the impact of COVID-19. Pandemic control depends on high vaccination rates and confidence levels among the population. This study determined COVID-19 vaccine acceptance and confidence levels among vaccinated Thai participants.

METHODS

An online cross-sectional study was conducted between 13 September 2021 and 14 January 2022 among individuals ≥ 18 years. An online questionnaire was distributed via social media platforms and posters in public places in Thailand. It included four components (demographic characteristics, COVID-19 vaccine regimens, vaccine acceptance, and confidence). Statistical analyses included a chi-squared test, Wilcoxon signed-rank test, and multivariate logistic regressions.

RESULTS

Approximately 88.4% of the participants accepted the vaccine. Almost half had confidence in 'unconcerned about vaccine side effects' (48.2%), 'trust in vaccine effectiveness' (44.3%) and 'trust in government vaccine policy' (43.4%). Multiple logistic regression indicated that males and high education significantly correlated with vaccine acceptance. Higher age (45-59 years and ≥ 60 years) and low monthly income (≤5,000 THB) were significantly associated with trust in government vaccine policy. The 1stCoronaVac/2ndCoronaVac/3rdBNT162b2 regimen group was significantly associated with unconcern about vaccine side effects compared to the 1stAZD1222/2ndAZD1222 regimen group.

CONCLUSIONS

Over half of vaccinated participants indicated concern about COVID-19 vaccine side effects and distrust in vaccine effectiveness and government policy; nonetheless, almost all took the COVID-19 vaccine. Participants who received the 1stCoronaVac/2ndCoronaVac/3rdBNT162b2 regimen were unconcerned about vaccine side effects. Some socio-demographic factors were associated with vaccine acceptance and high confidence, which should be sought while designing interventions to improve COVID-19 vaccination rates.

Examining spatial variation for immunisation coverage in pregnant women: A nationwide and geospatial retrospective cohort study in Aotearoa New Zealand

BACKGROUND

Maternal influenza and pertussis immunisation is crucial for protecting mothers during pregnancy and their babies in the first weeks of life against severe disease. We examined geospatial variation in maternal immunisation coverage among pregnant women in Aotearoa New Zealand and its health equity implications.

METHOD

We constructed a retrospective cohort including all pregnant women who delivered between 01 January 2013 and 31 December 2020 using administrative health datasets. Our outcomes were receipt of influenza or pertussis vaccine in any one of three relevant national databases (e.g. National Immunisation Register, Proclaims, or Pharmaceutical collection) during the eligible pregnancy.

RESULTS

Data from our retrospective cohort study show significant regional variation in maternal immunisation coverage for both influenza and pertussis from 2013 to 2020. Maximal coverage was around 50% in the best performing regions, which means that half of the women who were pregnant (183,737 women) were not protected. In addition, we found significant spatio-temporal variation and clustering of immunisation coverage. Our findings are interactively available to explore here: https://geohealthlab.shinyapps.io/hapumama/ CONCLUSION: Our study is one of the first to examine spatial variation in maternal vaccination coverage in pregnant women at a national level over space and time. This provides powerful tools to measure the impact of interventions to improve coverage at national and regional levels, with specific reference to inequities between ethnic groups, likely applicable to similar settings internationally.

Are maternal vaccines effective and safe for mothers and infants? A systematic review and meta-analysis of randomised controlled trials

INTRODUCTION

Maternal vaccination is a promising strategy to reduce the burden of vaccine-preventable diseases for mothers and infants. We aimed to provide an up-to-date overview of the efficacy and safety of all available maternal vaccines.

METHODS

We searched PubMed, Embase, CENTRAL and ClinicalTrials.gov on 1 February 2022, for phase III and IV randomised controlled trials (RCTs) that compared maternal vaccination against any pathogen with placebo or no vaccination. Primary outcomes were laboratory-confirmed or clinically confirmed disease in mothers and infants. Secondary safety outcomes included intrauterine growth restriction, stillbirth, maternal death, preterm birth, congenital malformations and infant death. Random effects meta-analysis were used to calculate pooled risk ratio's (RR). Quality appraisal was performed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE).

RESULTS

Six RCTs on four maternal vaccines, influenza, tetanus, diphtheria and pertussis (Tdap), pneumococcal and respiratory syncytial virus (RSV) were eligible. The overall risk of bias and certainty of evidence varied from low to high. Maternal influenza vaccination significantly reduced the number of laboratory-confirmed influenza cases (RR 0.58, 95% CI 0.42 to 0.79, event rate 57 vs 98, 2 RCTs, n=6003, I2=0%), and clinically confirmed influenza cases in mothers (RR 0.88, 95% CI 0.78 to 0.99, event rate 418 vs 472, 2 RCTs, n=6003, I2=0%), and laboratory-confirmed influenza in infants (RR 0.66, 95% CI 0.52 to 0.85, event rate 98 vs 148, 2 RCTs, n=5883, I2=0%), although this was not significant for clinically confirmed influenza in infants (RR 0.99, 95% CI 0.94 to 1.05, event rate 1371 vs 1378, 2 RCTs, n=5883, I2=0%). No efficacy data were available on maternal Tdap vaccination. Maternal pneumococcal vaccination did not reduce laboratory-confirmed and clinically confirmed middle ear disease (RR 0.49, 95% CI 0.24 to 1.02, event rate 9 vs 18, 1 RCT, n=133 and RR 0.88 95% CI 0.69 to 1.12, event rate 42 vs 47, 1 RCT, n=133, respectively), and clinically confirmed lower-respiratory tract infection (LRTI) (RR 1.08, 95% CI 0.82 to 1.43, event rate 18 vs 34, 1 RCT, n=70) in infants. Maternal RSV vaccination did not reduce laboratory-confirmed RSV LRTI in infants (RR 0.75, 95% CI 0.56 to 1.01, event rate 103 vs 71, 1 RCT, n=4527). There was no evidence of a significant effect of any of the maternal vaccines on the reported safety outcomes.

CONCLUSIONS

The few RCTs with low event rates suggest that, depending on the type of maternal vaccine, the vaccine might effectively prevent disease and within its size does not show safety concerns in mothers and infants.

PROSPERO REGISTRATION NUMBER

CRD42021235115.

Pertussis immunisation strategies to optimise infant pertussis control: A narrative systematic review

OBJECTIVE

Countries routinely offering acellular pertussis vaccine, where long-term protection is not sustained, have the challenge of selecting an optimal schedule to minimise disease among young infants. We conducted a narrative systematic review and synthesis of information to evaluate different pertussis immunisation strategies at controlling pertussis disease, hospitalisation, deaths, and vaccine effectiveness among young infants.

METHODS

We conducted a review of the literature on studies about the primary, booster, and/or maternal vaccination series and synthesised findings narratively. Countries offering the first three doses of vaccine within six-months of life and a booster on or before the second year or life were defined as accelerated primary and booster schedules, respectively. Countries offering primary and booster doses later were defined as extended primary and booster schedules. All search results were screened, and articles reviewed and reconciled, by two authors. The Risk of Bias in Non-randomised Studies of Intervention tool was used to evaluate the risk of bias.

FINDINGS

A total of 98 studies were included in the analyses and the following recurring themes were described: timing of vaccination, vaccine coverage, waning immunity/vaccine effectiveness, direct and indirect effectiveness, switching from an accelerated to extended schedule, impact of changes in testing. The risk of bias was generally low to moderate for most studies.

CONCLUSION

Comparing schedules is challenging and there was insufficient evidence to that one schedule was superior to another. Countries must select a schedule that maintains high vaccine coverage and reduced the risk of delaying the delivery vaccines to protect infants.

Reactogenicity, immunogenicity and breakthrough infections following heterologous or fractional second dose COVID-19 vaccination in adolescents (Com-COV3): A randomised controlled trial

BACKGROUND

This was the first study to investigate the reactogenicity and immunogenicity of heterologous or fractional second dose COVID-19 vaccine regimens in adolescents.

METHODS

A phase II, single-blind, multi-centre, randomised-controlled trial recruited across seven UK sites from September to November 2021, with follow-up visits to August 2022. Healthy 12-to-16 years olds were randomised (1:1:1) to either 30 µg BNT162b2 (BNT-30), 10 µg BNT162b2 (BNT-10), or NVX-CoV2373 (NVX), 8 weeks after a first 30 µg dose of BNT162b2. The primary outcome was solicited systemic reactions in the week following vaccination. Secondary outcomes included immunogenicity and safety. 'Breakthrough infection' analyses were exploratory.

FINDINGS

148 participants were recruited (median age 14 years old, 62% female, 26% anti-nucleocapsid IgG seropositive pre-second dose); 132 participants received a second dose. Reactions were mostly mild-to-moderate, with lower rates in BNT-10 recipients. No vaccine-related serious adverse events occurred. Compared to BNT-30, at 28 days post-second dose anti-spike antibody responses were similar for NVX (adjusted geometric mean ratio [aGMR]) 1.09 95% confidence interval (CI): 0.84, 1.42] and lower for BNT-10 (aGMR 0.78 [95% CI: 0.61, 0.99]). For Omicron BA.1 and BA.2, the neutralising antibody titres for BNT-30 at day 28 were similar for BNT-10 (aGMR 1.0 [95% CI: 0.65, 1.54] and 1.02 [95% CI: 0.71, 1.48], respectively), but higher for NVX (aGMR 1.7 [95% CI: 1.07, 2.69] and 1.43 [95% CI: 0.96, 2.12], respectively). Compared to BNT-30, cellular immune responses were greatest for NVX (aGMR 1.73 [95% CI: 0.94, 3.18]), and lowest for BNT-10 (aGMR 0.65 [95% CI: 0.37, 1.15]) at 14 days post-second dose. Cellular responses were similar across the study arms by day 236 post-second dose. Amongst SARS-CoV-2 infection naïve participants, NVX participants had an 89% reduction in risk of self-reported 'breakthrough infection' compared to BNT-30 (adjusted hazard ratio [aHR] 0.11 [95% CI: 0.01, 0.86]) up until day 132 after second dose. BNT-10 recipients were more likely to have a 'breakthrough infection' compared to BNT-30 (aHR 2.14 [95% CI: 1.02, 4.51]) up to day 132 and day 236 post-second dose. Antibody responses at 132 and 236 days after second dose were similar for all vaccine schedules.

INTERPRETATION

Heterologous and fractional dose COVID-19 vaccine schedules in adolescents are safe, well-tolerated and immunogenic. The enhanced performance of the heterologous schedule using NVX-CoV2373 against the Omicron SARS-CoV-2 variant suggests this mRNA prime and protein-subunit boost schedule may provide a greater breadth of protection than the licensed homologous schedule.

FUNDING

National Institute for Health Research and Vaccine Task Force.

TRIAL REGISTRATION

International Standard Randomised Controlled Trial Number registry: 12348322.

Factors associated with full vaccination and zero vaccine dose in children aged 12-59 months in 6 health districts of Cameroon

BACKGROUND

Routine immunisation coverage in Cameroon is still below the target of the national Expanded Programme on Immunisation (EPI), with only 42% of children fully immunised according to Demographic and Health Survey (DHS) report in 2018. The objective of this study was to evaluate factors associated with full immunisation and zero-dose in Cameroonian children.

METHODS

A two-stage cross-sectional cluster survey was conducted in Yaoundé in November 2021, targeting children aged 12-59 months. The clusters were chosen with probability proportionate to population size (PPS), and households selected by restricted sampling technique. Data were collected from the vaccination card of the child or from parents' recall, if the card was not available, using electronic forms with tablets. Using R (version 4.1.0.), the proportion of fully immunised children was calculated. The household wealth index was described using principal component analysis, and factors associated with full immunisation assessed with multiple logistics regression. The threshold of statistical significance was set at 5%.

FINDINGS

A total, 273 children aged 12-59 months enrolled; 37% of participants were fully immunised, and 16% had never received any vaccine. Mother's level of education: Primary (OR = 3.59, p = 0.0200), high school (OR = 3.68, p = 0.0400*), and higher education (OR = 8.25, p = 0.0018), and sharing household with biological father (OR = 2.11, p = 0.0305) were significantly associated with full vaccination. Living in a richer (3rd-5th wealth quintiles) household (OR = 0.25, p = 0.0053); mother's education: Primary (OR = 0.07, p = 0.0271) and Higher education (OR = 0.10, p = 0.0419), living with the mother (OR = 0.05, p =  < 0.0001) and living with the father (OR = 0.22, p = 0.0253) had significant negative association with zero-dose in children.

CONCLUSION

The proportion of fully vaccinated children in Yaounde is lower than the national average. Children from poor homes and those borne by uneducated mother have higher odds of not being vaccinated. Immunisation programmes in Yaounde need to be stepped up to improve coverage. Equally, there is a need to reconsider how the poor can the better reached with immunisation services.

Applying the COM-B behaviour model to understand factors which impact school immunisation nurses' attitudes towards designing and delivering a HPV educational intervention in post-primary schools for 15-17 year old students in Northern Ireland, UK

INTRODUCTION

Human Papilloma Virus (HPV) is responsible for the development of cervical, vaginal, vulvar, penile, oropharyngeal and anal cancers. Throughout the UK, Immunisation nurses (IMNs) deliver school-based HPV vaccinations to students 12-13 years old. Providing HPV education to 15-17 year old students may promote decision-making regarding their sexual health and award opportunity for unvaccinated students to self-consent to the vaccination. This study aims to explore the perceptions of IMNs regarding the value of providing HPV education to 15-17 year old students and to explore whether IMNs feel that the design/delivery of this education should form part of their professional role.

METHODS

Six focus groups were conducted online with IMNs from all five Health and Social Care Trusts in Northern Ireland, UK, between January-June 2021. Data were analysed using the COM-B model to identify factors that might influence IMNs' behaviour towards designing/delivering this education for 15-17 year old students.

RESULTS

IMNs were highly motivated to design and deliver this HPV education. Facilitators promoting this behaviour included their specialist training, their previous sexual health teaching experience and their desire to educate young people. Barriers negatively influencing this behaviour included lack of time/resources, parental influences, lack of school support and lack of teaching/presentation skills training.

CONCLUSION

IMNs feel that they are the most appropriate professionals to design/deliver HPV education for 15-17 year old students. National policy change, based on collaboration between the Public Health Agency and Education Authority, is a key factor in facilitating IMNs to implement this school-based HPV education intervention.

Interventions for increasing the uptake of immunisations in healthcare workers: A systematic review

OBJECTIVE

This systemic review aimed to evaluate the effectiveness of interventions for increasing the uptake of immunisation in healthcare workers (HCWs) compared to no or alternative interventions.

METHODS

A systematic review was undertaken (until March 2022) using a search strategy established a priori to capture studies that examined the effect of interventions on vaccination levels in HCWs. We included randomised controlled trials (RCT), cluster RCTs, controlled before-after (CBA) studies and interrupted time-series (ITS) studies. We described studies descriptively and synthesized results with a fixed-effect or random-effects model meta-analysis, where appropriate. The risk of bias was assessed for each study; the quality evidence per comparison was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

We identified three RCTs, six cluster RCTs and four ITS studies. There was a diverse range of interventions; many included an educational component. Based on the evidence examined the following may be effective strategies in increasing the proportion of HCWs vaccinated: policy interventions, targeted and multicomponent strategies, tailored programs directed at management, physician delivered education with a vaccine 'champion' and individual decision analysis. Limited eligible studies restricted synthesis and interpretation of findings. No studies evaluated the effectiveness of legislation. Nor did we find studies evaluating the effectiveness of incentives on their own or studies focusing solely on improving access to vaccination. We judged all the studies as either unclear or high risk of bias.

CONCLUSION

Few robust studies that evaluate interventions to increase vaccination in HCWs are available. A limitation of this systematic review is that interventions are diverse, poorly reported and few were sufficiently alike to combine in an evaluation. More research on the effects of interventions to increase vaccination in HCWs is required, this should address a variety of vaccines and not just influenza vaccination.

Evaluation of murine OX40L-murine IgG1(MM1) fusion protein on immunogenicity against L. mexicana infection in BALB/c mice

The majority of OX40L is found on professional antigen-presenting cells (APC), the potency of OX40L to enhance the immunogenicity of potential vaccines against leishmania is not yet fully investigated. There is no report of administration of OX40L on cutaneous leishmaniasis either in therapy or prophylactic immunisation and the present study for the first time reports the effect of OX40L on L. mexicana infection. In this study, B9B8E2 cells were transfected with the murine OX40L and IgG1 plasmids, were used to produce the mOX40-mIgG1 (MM1). The therapeutic effects of MM1(mOX40L-mIgG1) was tested in a challenge experiment using L. mexicana infected BALB/c mice. Mice received two doses of MM1, on day 3 and 7 after the infection. Mice receiving MM1 generated an inflammatory reaction a few days after the injection of the OX40L, which was gradually dampened and finally disappeared 3 weeks later. There was a significant delay in the growth of developing lesions in mice receiving OX40L compared to controls injected with PBS and the size of lesions in the group receiving MM1 was significantly smaller than that of injected with either PBS. 40% of mice given MM1 remained lesion free for two months, when experiments were terminated. The results clearly indicate the high therapeutic effect of mOX40L-mIgG1 fusion protein in L. mexicana infection. The effect of OX40L on the enhancement of immunisation, needs to be further investigated for developing new vaccine strategies.

Infant mortality rates and pneumococcal vaccines: a time-series trend analysis in 194 countries, 1950-2020

Pneumonia due to Streptococcus pneumoniae (pneumococcus) is a major cause of mortality in infants (children under 1 year of age), and pneumococcal conjugate vaccines (PCVs), delivered during the first year of life, are available since the year 2000. Given those two premises, the conclusion follows logically that favourable impact reported for PCVs in preventing pneumococcal disease should be reflected in the infant mortality rates (IMRs) from all causes. Using publicly available datasets, country-level IMR estimates from UNICEF and PCV introduction status from WHO, country-specific time series analysed the temporal relationship between annual IMRs and the introduction of PCVs, providing a unique context into the long-term secular trends of IMRs in countries that included and countries that did not include PCVs in their national immunisation programmes. PCV status was available for 194 countries during the period 1950-2020: 150 (77.3%) of these countries achieved nationwide PCV coverage at some point after the year 2000, 13 (6.7%) achieved only partial or temporary PCV coverage, and 31 (15.9%) never introduced PCVs to their population. One hundred and thirty-nine (92.7%) of countries that reported a decreasing (negative) trend in IMR, also reported a strong correlation with decreasing maternal mortality rates (MMRs), suggesting an improvement in overall child/mother healthcare. Conversely, all but one of the countries that never introduced PCVs in their national immunisation programme also reported a decreasing trend in IMR that strongly correlates with MMRs. IMRs have been decreasing for decades all over the world, but this latest decrease may not be related to PCVs.

Understanding the factors that influence communication about COVID-19 vaccines with patients: Perspectives of Australian immunisation providers

Background

COVID-19 immunisation providers have been at the forefront of the pandemic, and their ability to communicate effectively with patients is key to encouraging COVID-19 vaccine acceptance and uptake. This study explored providers' perspectives on the factors influencing communication with patients about COVID-19 vaccines.

Methods

We used an explanatory-sequential mixed-methods approach to conduct the study between December 2021 and March 2022. Phase I involved a cross-sectional survey with immunisation providers in New South Wales (n = 341; 189 general practitioners, 118 nurses and 34 pharmacists), followed by Phase II: semi-structured, in-depth qualitative interviews (n = 19; 10 nurses, 9 pharmacists). We generated descriptive results for the survey. We analysed the qualitative data thematically using an inductive approach.

Results

Almost half of survey participants reported communicating often with people who were hesitant about COVID-19 vaccines (49 %; 166/341), however, 21 % (71/341) reported inadequate time to address concerns during consultations. Interview participants reported communication challenges, including time constraints, difficulties addressing and eliciting patient concerns, and keeping up to date with changing information. Conversely, interview participants reported that easy access to government information resources, time to learn about COVID-19 vaccines proactively, knowing about and being able to use tailored strategies to support Aboriginal and Torres Strait Islander and CALD patients were helpful when communicating with patients.

Conclusions

Immunisation providers play an important role in patient vaccine acceptance and uptake. Our findings indicate that whilst providers were largely confident in their interactions with patients, further communication support would strengthen providers' skills in communicating with patients who have questions and concerns about COVID-19 vaccines.

Optimising DTwP-containing vaccine infant immunisation schedules (OptImms) - a protocol for two parallel, open-label, randomised controlled trials

BACKGROUND

Universal immunisation is the cornerstone of preventive medicine for children, The World Health Organisation (WHO) recommends diphtheria-tetanus-pertussis (DTP) vaccine administered at 6, 10 and 14 weeks of age as part of routine immunisation. However, globally, more than 17 unique DTP-containing vaccine schedules are in use. New vaccines for other diseases continue to be introduced into the infant immunisation schedule, resulting in an increasingly crowded schedule. The OptImms trial will assess whether antibody titres against pertussis and other antigens in childhood can be maintained whilst adjusting the current Expanded Programme on Immunisation (EPI) schedule to provide space for the introduction of new vaccines.

METHODS

The OptImms studies are two randomised, five-arm, non-inferiority clinical trials in Nepal and Uganda. Infants aged 6 weeks will be randomised to one of five primary vaccination schedules based on age at first DTwP-vaccination (6 versus 8 weeks of age), number of doses in the DTwP priming series (two versus three), and spacing of priming series vaccinations (4 versus 8 weeks). Additionally, participants will be randomised to receive their DTwP booster at 9 or 12 months of age. A further sub-study will compare the co-administration of typhoid vaccine with other routine vaccines at one year of age. The primary outcome is anti-pertussis toxin IgG antibodies measured at the time of the booster dose. Secondary outcomes include antibodies against other vaccine antigens in the primary schedule and their safety.

DISCUSSION

These data will provide key data to inform policy decisions on streamlining vaccination schedules in childhood.

TRIAL REGISTRATIONS

ISRCTN12240140 (Nepa1, 7th January 2021) and ISRCTN6036654 (Uganda, 17th February 2021).

"She vaccinated my baby and that's all…" Immunisation decision-making and experiences among refugee mothers resettled in Aotearoa New Zealand

BACKGROUND

To prevent disease outbreaks, refugee children must be age-appropriately immunised. This qualitative study gained an in-depth understanding of refugee mothers' vaccine decision-making and experiences accessing immunisation services for their children post-resettlement in Aotearoa New Zealand.

METHODS

An interpretive description methodology involving focus groups with refugee mothers (N = 45) was conducted in Auckland, one of the resettlement locations. Mothers were asked about their perceptions of vaccine-preventable diseases and vaccines, their experiences of attending immunisation events, and their suggestions for improvements to immunisation services. Data were analysed following the phases of reflexive thematic analysis.

RESULTS

Four themes were constructed. Do I have a choice? Mothers displayed pro-vaccination sentiments and parental obligation to vaccinate their children to protect their health, which underpinned their compliance with the national vaccine schedule. Transnational vaccine perceptions and behaviours It was evident that comparing their health experiences in their origin countries reinforced their positive perceptions of and trust in vaccines, health providers and their recommendations, the health system and government in New Zealand. Information sharing with their transnational networks had the potential to influence vaccine perceptions and behaviours in home and host countries. Unanswered questions and concerns Mothers discussed how many of their questions and concerns about immunisations and post-vaccine management went unanswered. Relationships and experiences matter Mothers stressed the importance of who vaccinated their child and how it was administered, highlighting that health providers' demeanour and competence influence their immunisation experiences.

CONCLUSIONS

Health providers are encouraged to focus on creating a positive immunisation experience for refugee background families. Qualified interpreters and provision of culturally and linguistically appropriate information are required. Transnationalism at the individual level appears to influence vaccine perceptions and behaviours among refugee-background mothers. Future research focusing on caregivers with child(ren) who are not fully vaccinated would be beneficial.

Persistence of immune responses after heterologous and homologous third COVID-19 vaccine dose schedules in the UK: eight-month analyses of the COV-BOOST trial

BACKGROUND

COV-BOOST is a multicentre, randomised, controlled, phase 2 trial of seven COVID-19 vaccines used as a third booster dose in June 2021. Monovalent messenger RNA (mRNA) COVID-19 vaccines were subsequently widely used for the third and fourth-dose vaccination campaigns in high-income countries. Real-world vaccine effectiveness against symptomatic infections following third doses declined during the Omicron wave. This report compares the immunogenicity and kinetics of responses to third doses of vaccines from day (D) 28 to D242 following third doses in seven study arms.

METHODS

The trial initially included ten experimental vaccine arms (seven full-dose, three half-dose) delivered at three groups of six sites. Participants in each site group were randomised to three or four experimental vaccines, or MenACWY control. The trial was stratified such that half of participants had previously received two primary doses of ChAdOx1 nCov-19 (Oxford-AstraZeneca; hereafter referred to as ChAd) and half had received two doses of BNT162b2 (Pfizer-BioNtech, hereafter referred to as BNT). The D242 follow-up was done in seven arms (five full-dose, two half-dose). The BNT vaccine was used as the reference as it was the most commonly deployed third-dose vaccine in clinical practice in high-income countries. The primary analysis was conducted using all randomised and baseline seronegative participants who were SARS-CoV-2 naïve during the study and who had not received a further COVID-19 vaccine for any reason since third dose randomisation.

RESULTS

Among the 817 participants included in this report, the median age was 72 years (IQR: 55-78) with 50.7% being female. The decay rates of anti-spike IgG between vaccines are different among both populations who received initial doses of ChAd/ChAd and BNT/BNT. In the population that previously received ChAd/ChAd, mRNA vaccines had the highest titre at D242 following their vaccine dose although Ad26. COV2. S (Janssen; hereafter referred to as Ad26) showed slower decay. For people who received BNT/BNT as their initial doses, a slower decay was also seen in the Ad26 and ChAd arms. The anti-spike IgG became significantly higher in the Ad26 arm compared to the BNT arm as early as 3 months following vaccination. Similar decay rates were seen between BNT and half-BNT; the geometric mean ratios ranged from 0.76 to 0.94 at different time points. The difference in decay rates between vaccines was similar for wild-type live virus-neutralising antibodies and that seen for anti-spike IgG. For cellular responses, the persistence was similar between study arms.

CONCLUSIONS

Heterologous third doses with viral vector vaccines following two doses of mRNA achieve more durable humoral responses compared with three doses of mRNA vaccines. Lower doses of mRNA vaccines could be considered for future booster campaigns.

The use of technology in vaccine safety communication: A systematic review of randomised controlled trials

OBJECTIVES

To identify technologies used in vaccine safety communication and evaluate their impact on vaccination intention, uptake, knowledge, attitude, and perceptions of consumers.

METHODS

We searched 6 electronic databases to identify randomised controlled trials assessing the impact of using technology in vaccine safety communication. The Cochrane Collaboration's tool for assessing risk of bias was used to evaluate each study.

RESULTS

We included 22 studies involving 27,109 participants from 8 countries; 15 studies assessed the use of videos and 7 examined innovative technologies. Using videos significantly improved knowledge (n = 3) and participant engagement (n = 2) compared to printed material. Among the innovative technologies, the use of virtual reality, and smartphone applications incorporating social networking or gamification significantly increased vaccination knowledge, confidence, and engagement. The studies showed that narrative messaging increased perceived disease severity (n = 2) and vaccination intention (n = 2).

CONCLUSIONS

While the use of innovative technologies is increasing, videos currently remain the most popular technology for vaccine safety communication. Communication technology, particularly with narrative messaging, improves patient engagement and comprehension.

PRACTICE IMPLICATIONS

Health authorities should increase focus on using videos and smartphone applications for vaccine safety communication. Collaboration among stakeholders is essential to develop guidelines on effective message content to complement the technology.

Global and regional burden of attributable and associated bacterial antimicrobial resistance avertable by vaccination: modelling study

INTRODUCTION

Antimicrobial resistance (AMR) is a global health threat with 1.27 million and 4.95 million deaths attributable to and associated with bacterial AMR, respectively, in 2019. Our aim is to estimate the vaccine avertable bacterial AMR burden based on existing and future vaccines at the regional and global levels by pathogen and infectious syndromes.

METHODS

We developed a static proportional impact model to estimate the vaccination impact on 15 bacterial pathogens in terms of reduction in age-specific AMR burden estimates for 2019 from the Global Research on Antimicrobial Resistance project in direct proportion to efficacy, coverage, target population for protection, and duration of protection of existing and future vaccines.

RESULTS

The AMR burden avertable by vaccination in 2019 was highest for the WHO Africa and South-East Asia regions, for lower respiratory infections, tuberculosis, and bloodstream infections by infectious syndromes, and for Mycobacterium tuberculosis and Streptococcus pneumoniae by pathogen. In the baseline scenario for vaccination of primary age groups against 15 pathogens, we estimated vaccine-avertable AMR burden of 0.51 (95% UI 0.49-0.54) million deaths and 28 (27-29) million disability-adjusted life-years (DALYs) associated with bacterial AMR, and 0.15 (0.14-0.17) million deaths and 7.6 (7.1-8.0) million DALYs attributable to AMR globally in 2019. In the high-potential scenario for vaccination of additional age groups against seven pathogens, we estimated vaccine-avertable AMR burden of an additional 1.2 (1.18-1.23) million deaths and 37 (36-39) million DALYs associated with AMR, and 0.33 (0.32-0.34) million deaths and 10 (9.8-11) million DALYs attributable to AMR globally in 2019.

CONCLUSION

Increased coverage of existing vaccines and development of new vaccines are effective means to reduce AMR, and this evidence should inform the full value of vaccine assessments.

Vaccine access, equity and justice: COVID-19 vaccines and vaccination

Although significant progress has been made in achieving goals for COVID-19 vaccine access, the quest for equity and justice remains an unfinished agenda. Vaccine nationalism has prompted calls for new approaches to achieve equitable access and justice not only for vaccines but also for vaccination. This includes ensuring country and community participation in global discussions and that local needs to strengthen health systems, address issues related to social determinants of health, build trust and leverage acceptance to vaccines, are addressed. Regional vaccine technology and manufacturing hubs are promising approaches to address access challenges and must be integrated with efforts to ensure demand. The current situation underlines the need for access, demand and system strengthening to be addressed along with local priorities for justice to be achieved. Innovations to improve accountability and leverage existing platforms are also needed. Sustained political will and investment is required to ensure ongoing production of non-pandemic vaccines and sustained demand, particularly when perceived threat of disease appears to be waning. Several recommendations are made to govern towards justice including codesigning the path forward with low-income and middle-income countries; establishing stronger accountability measures; establishing dedicated groups to engage with countries and manufacturing hubs to ensure that the affordable supply and predictable demand are in balance; addressing country needs for health system strengthening through leveraging existing health and development platforms and delivering on product presentations informed by country needs. Even if difficult, we must converge on a definition of justice well in advance of the next pandemic.

Factors, enablers and challenges for COVID-19 vaccine development

The COVID-19 pandemic triggered a sense of vulnerability and urgency that led to concerted actions by governments, funders, regulators and industry to overcome traditional challenges for the development of vaccine candidates and to reach authorisation. Unprecedented financial investments, massive demand, accelerated clinical development and regulatory reviews were among the key factors that contributed to accelerating the development and approval of COVID-19 vaccines. The rapid development of COVID-19 vaccines benefited of previous scientific innovations such as mRNA and recombinant vectors and proteins. This has created a new era of vaccinology, with powerful platform technologies and a new model for vaccine development. These lessons learnt highlight the need of strong leadership, to bring together governments, global health organisations, manufacturers, scientists, private sector, civil society and philanthropy, to generate innovative, fair and equitable access mechanisms to COVID-19 vaccines for populations worldwide and to build a more efficient and effective vaccine ecosystem to prepare for other pandemics that may emerge. With a longer-term view, new vaccines must be developed with incentives to build expertise for manufacturing that can be leveraged for low/middle-income countries and other markets to ensure equity in innovation, access and delivery. The creation of vaccine manufacturing hubs with appropriate and sustained training, in particular in Africa, is certainly the way of the future to a new public health era to safeguard the health and economic security of the continent and guarantee vaccine security and access, with however the need for such capacity to be sustained in the interpandemic period.

COVID-19 vaccines and the pandemic: lessons learnt for other neglected diseases and future threats

Through the experiences gained by accelerating new vaccines for both Ebola virus infection and COVID-19 in a public health emergency, vaccine development has benefited from a 'multiple shots on goal' approach to new vaccine targets. This approach embraces simultaneous development of candidates with differing technologies, including, when feasible, vesicular stomatitis virus or adenovirus vectors, messenger RNA (mRNA), whole inactivated virus, nanoparticle and recombinant protein technologies, which led to multiple effective COVID-19 vaccines. The challenge of COVID-19 vaccine inequity, as COVID-19 spread globally, created a situation where cutting-edge mRNA technologies were preferentially supplied by multinational pharmaceutical companies to high-income countries while low and middle-income countries (LMICs) were pushed to the back of the queue and relied more heavily on adenoviral vector, inactivated virus and recombinant protein vaccines. To prevent this from occurring in future pandemics, it is essential to expand the scale-up capacity for both traditional and new vaccine technologies at individual or simultaneous hubs in LMICs. In parallel, a process of tech transfer of new technologies to LMIC producers needs to be facilitated and funded, while building LMIC national regulatory capacity, with the aim of several reaching 'stringent regulator' status. Access to doses is an essential start but is not sufficient, as healthcare infrastructure for vaccination and combating dangerous antivaccine programmes both require support. Finally, there is urgency to establish an international framework through a United Nations Pandemic Treaty to promote, support and harmonise a more robust, coordinated and effective global response.