Estimating the impact of COVID-19 vaccine inequities: a modeling study

COVID-19 vaccine knowledge and acceptance among the Libyan population: A cross-sectional study

We aim to identify Libyans' knowledge, attitudes, and acceptance regarding the COVID-19 vaccine. A cross-sectional survey was electronically distributed to the Libyan population aged 18 and older between May and September 2023. The questionnaire had three sections: socio-demographics, COVID-19 vaccination and infection, and knowledge and attitudes toward the COVID-19 vaccine. The chi-square test was used to assess the associations. A total of 1,043 respondents completed the questionnaire. Of these, 590 (56.6%) were vaccinated, and 453 (43.4%) were unvaccinated. Only age, educational level, employment status, history of COVID-19 infection, and source of information had a significant association with vaccination status; all shared a p-value <.05. However, Monthly income did not. Regarding knowledge, 63.7% agreed that vaccines in general are an effective way to prevent and control infectious diseases, and 76.6% agreed that they can prevent disease and mortality. However, regarding COVID-19 vaccine, 48.4% agreed that the benefits outweigh the risks. Regarding COVID-19 safety, 40.8% responded that COVID-19 vaccines are only slightly safe or not safe at all. COVID-19 vaccine acceptance was at 57.2%, and only age and source of information were significantly associated. Those who held favorable views were more likely to accept the vaccine, while those who had concerns about safety were more vaccine hesitant. There is a gap between the perception of the COVID-19 vaccine compared to other vaccines among Libyans. Our study revealed that 57.2% of Libyans accept the COVID-19 vaccine. However, only 34% of the Libyan population is vaccinated. A comprehensive health policy is needed.

How the COVID-19 pandemic affected routine child vaccination: an integrative review

BACKGROUND

Child immunization plays a critical role in preventing numerous diseases. However, the COVID-19) pandemic has profoundly disrupted healthcare systems globally, including routine child vaccination programs.

OBJECTIVE

To provide an overview of the reduction in vaccine coverage among infants and children during the pandemic and analyze the potential impacts of decreased child immunization during this period.

METHODS

A comprehensive search was conducted using the MeSH terms "Child," "Vaccination", and "COVID-19," along with their synonyms. Systematic reviews published between March 11, 2020, and June 1, 2023, in Portuguese or English were included. Databases searched included PubMed, BVS (Biblioteca Virtual em Saúde), Embase, and Scopus. Two blinded independent reviewers performed the selection process, with conflicts resolved by a third reviewer. The AMSTAR-II tool was used to assess the methodological quality of the included studies.

RESULTS

Of the 1,534 eligible articles, only 13 addressed the pandemic's impact on children's vaccination coverage. Most studies involved multiple countries and reported a significant decrease in children's vaccination coverage due to the COVID-19 pandemic.

CONCLUSION

The findings were heterogeneous but consistently highlighted the substantial impact of the COVID-19 pandemic on routine vaccination coverage in most countries. Further research is needed to explore the epidemiological consequences of disruptions to vaccination schedules, potentially guiding public policies and raising awareness about the importance of adhering to health protection programs.

Structural inequalities exacerbate infection disparities

During the COVID-19 pandemic, the world witnessed a disproportionate infection rate among marginalized and low-income groups. Despite empirical evidence suggesting that structural inequalities in society contribute to health disparities, there has been little attempt to offer a computational and theoretical explanation to establish its plausibility and quantitative impact. Here, we focus on two aspects of structural inequalities: wealth inequality and social segregation. Our computational model demonstrates that (a) due to the inequality in self-quarantine ability, the infection gap widens between the low-income and high-income groups, and the overall infected cases increase, (b) social segregation between different socioeconomic status (SES) groups intensifies the disease spreading rates, and (c) the second wave of infection can emerge due to a false sense of safety among the medium and high SES groups. By performing two data-driven analyses, one on the empirical network and economic data of 404 metropolitan areas of the United States and one on the daily Covid-19 data of the City of Chicago, we verify that higher segregation leads to an increase in the overall infection cases and higher infection inequality across different ethnic/socioeconomic groups. These findings together demonstrate that reducing structural inequalities not only helps decrease health disparities but also reduces the spread of infectious diseases overall.

Inequality in COVID-19 vaccine acceptance and uptake: A repeated cross-sectional analysis of COVID vaccine acceptance and uptake in 13 countries

Background COVID-19 vaccine hesitancy was a key barrier to ending the pandemic via mass immunisation. Objectives Assess magnitudes and differences in socioeconomic inequality in stated COVID-19 vaccine acceptance (hesitancy) and uptake. Methods Online surveys were conducted in 13 countries, collecting data from 15,337 and 18,189 respondents respectively. The investigation compares socioeconomic inequality in reported vaccine acceptance, measured in 2020-21 and subsequent uptake of vaccination in 2022. Inequalities are quantified using differences, ratios and the Erreygers adjusted concentration index. A regression decomposition approach is used to identify factors associated with inequality. Results Mean uptake levels were 87 %, while acceptance was lower at 77 %. The difference between the richest and the poorest quintile was as large as 23 percentage points in acceptance and 30 p.p. in uptake, both observed in France. Acceptance and uptake were pro-rich (regressive) in most countries. Nine countries reported pro-rich inequality in acceptance, and eight in uptake. Uptake was significantly less regressive than acceptance in Australia, China, India, and USA. Australia and Colombia were the only countries where vaccination uptake was pro-poor (progressive). Age, marital status and political ideology were correlated with socioeconomic inequalities in several countries in both waves, while gender and education were associated with acceptance, and health levels with uptake. Conclusion We found significant inequalities in vaccination acceptance and uptake across countries but inequality was generally lower in vaccine uptake than in acceptance. This suggests that inequalities can be reduced over time if adequate policies are in place to overcome hesitancy and reduce inequalities.

Specimen and data sharing to advance research and development on Zika virus

For diseases with epidemic potential, specimen and data sharing is crucial for sustained research and development of medical countermeasures such as diagnostics, therapeutics, and vaccines. In the case of Zika virus, although a global framework for specimen and data sharing to advance research and development is highly desirable, challenges related to legal, ethical, and intellectual property issues persist. Since the 2015-16 Zika virus outbreak, regional laboratory networks and research partnerships have made some progress in specimen and data sharing among some Zika virus-endemic countries. Pragmatic steps such as securing funds for augmenting laboratory capacity, building biobanks within public health laboratory infrastructures in low-income and middle-income countries, clearly defining the specimens and data that need to be collected, developing standardised protocols, harmonising data system interoperability to facilitate sharing, and defining mechanisms for benefit sharing will pave the way for timely development and deployment of medical countermeasures in public health emergencies.

Social inequality and cultural factors impact the awareness and reaction during the cryptic transmission period of pandemic

The World Health Organization (WHO) declared the COVID-19 outbreak a Public Health Emergency of International Concern on 2020 January 31. However, rumors of a "mysterious virus" had already been circulating in China in 2019 December, possibly preceding the first confirmed COVID-19 case. Understanding how awareness about an emerging pandemic spreads through society is vital not only for enhancing disease surveillance, but also for mitigating demand shocks and social inequities, such as shortages of personal protective equipment and essential supplies. Here we leverage a massive e-commerce dataset comprising 150 billion online queries and purchase records from 94 million people to detect the traces of early awareness and public response during the cryptic transmission period of COVID-19. Our analysis focuses on identifying information gaps across different demographic cohorts, revealing significant social inequities and the role of cultural factors in shaping awareness diffusion and response behaviors. By modeling awareness diffusion in heterogeneous social networks and analyzing online shopping behavior, we uncover the evolving characteristics of vulnerable populations. Our findings expand the theoretical understanding of awareness spread and social inequality in the early stages of a pandemic, highlighting the critical importance of e-commerce data and social network data in effectively and timely addressing future pandemic challenges. We also provide actionable recommendations to better manage and mitigate dynamic social inequalities in public health crises.

Health behavior and social crisis in the era of COVID-19 in Malawi: A decolonizing approach to a qualitative study

BACKGROUND

The rapid spread and severity of COVID-19 brought major health challenges and dealt a heavy blow to key health services and daily life in Africa, including Malawi.

PURPOSE

To explore and examine the impact of the COVID-19 pandemic on cervical cancer (CC) prevention behavior in Malawi through a decolonized lens.

METHODS

A qualitative descriptive study informed by a decolonized perspective was conducted during the COVID-19 pandemic. A purposive sampling was taken from 17 key informant interviews, including, seven Malawian women living with HIV infection (WLWHIV).

RESULTS

Themes explored were that COVID-19 was indiscriminate towards not only health deterioration but also a social crisis and health was no longer an individual problem but a public and global issue across borders.

CONCLUSION

To uproot global health inequities, templates revolved around Western ways of knowing over national and global health need to be reexamined and methods reinvented to be relevant to local ways of knowing.

Parental experience with childhood COVID-19 vaccines and factors associated with parental hesitancy despite being vaccinated: findings of a cross-sectional analysis from Pakistan and implications for the future

OBJECTIVES

This study examined parental experiences with COVID-19 vaccination and factors contributing to COVID-19 vaccine hesitancy (CVH) among them to help guide future policy initiatives.

DESIGN

Cross-sectional study.

SETTING

Lahore, the second largest metropolis in Pakistan.

PARTICIPANTS

This study was conducted among parents residing in Lahore from March to April 2023. Participants were recruited via convenience sampling.

OUTCOME MEASURES

Data were collected using a prevalidated questionnaire that consisted of four sections: (1) informed consent, (2) demographic details, (3) COVID-19 vaccine uptake in children aged 5-17 years, parents' experience with childhood COVID-19 vaccination and their intention to vaccinate their unvaccinated children and (4) a modified 5C scale tailored to determine parents' confidence, complacency, constraints, calculation and collective responsibility with regard to COVID-19 vaccination.

RESULTS

This study included 414 parents (median age=37 years; mothers=62%). COVID-19 vaccination rates for children in the age groups 12-17 years and 5-11 years were 72.5% and 30.1%, respectively. Transient adverse events following immunisation were reported by 32.7% of parents. Of parents with unvaccinated children aged 12-17 years, only 35% intended to vaccinate them. The majority of parents were not willing to vaccinate their children below 11 years of age. Parents with a self-reported positive history of COVID-19 disease (OR=2.531, p=0.016), and confident in the vaccine's safety and efficacy (OR=1.968, p=0.010), were more inclined to vaccinate their 5-11 years. In terms of vaccination of children below 5 years, confidence in the vaccine (OR=2.942, p=0.003) and a sense of collective responsibility were positive predictors (OR=2.260, p=0.035), while calculation was identified as a negative predictor of parents' intention to vaccinate their under 5 years (OR=0.421, p=0.018).

CONCLUSION

CVH was significantly higher among parents of children aged 5-11 years and children younger than 5 years old. Priority should be given by health authorities to address parental concerns about vaccines and ensure that parents understand the significance of vaccination in protecting their children, to increase vaccination rates. This is because hesitancy towards one specific vaccine can negatively impact hesitancy rates in general.

Psychological antecedents of vaccine inequity: keys to improve the rates of vaccination

BACKGROUND

The World Health Organization (WHO) stresses the importance of worldwide vaccine coverage of coronavirus-19 (COVID-19) vaccination. This study fills a critical gap in the literature by providing empirical evidence on the factors influencing COVID-19 vaccine hesitancy and inequity in the Middle East and North Africa (MENA) region. This study investigated the determinants of psychological antecedents and other factors behind COVID-19 vaccination and their role in vaccine coverage in MENA.

METHODS

An anonymous online cross-sectional survey was conducted in 11 MENA countries (Egypt, Sudan, Kuwait, Saudi Arabia, Morocco, Iraq, Yemen, Lebanon, Libya, Afghanistan, and Pakistan). The minimum required sample size from each country was 307, which was increased to 330 to accommodate a non-response rate of 7%. A multilevel logistic regression model was used to capture the clustering of observations in each country and estimate the explanatory variables' effects on each item of the 5C components of the psychological antecedents scale namely (confidence, constraints, complacency, calculation, and collective responsibility).

RESULTS

The total number of respondents was 3630, 40.5% of them were between the ages of 18 and 25 years, 61.1% were females, 54.0% completed university education, 55.8% were unmarried, 19.5% had chronic diseases, 43.7% reported a previous COVID-19 and 42.4% had relatives who died from COVID-19. Much of the variation in the log of the odds in each item of the 5Cs was due to heterogeneity between different countries (intraclass correlation > 0.05). Therefore, this variability confirms the various effects of psychological antecedents on vaccination coverage, stimulating vaccination inequity among them. Increasing confidence in vaccines and collective responsibility towards relatives and the community is related to increasing acceptance of the COVID-19 vaccine. The reduction in complacency, calculations, and constraints was found to be associated with acceptance of the COVID-19 vaccine.

CONCLUSIONS

This study is novel in shedding light on the importance of psychological determinants as hidden causes of vaccine inequities by using a multilevel logistic regression model for COVID-19 vaccination intention. The findings suggest that targeted interventions addressing socio-demographic factors, psychological antecedents, and accessibility barriers are essential to mitigate vaccine inequity and improve vaccination rates.

Real-time estimates of the emergence and dynamics of SARS-CoV-2 variants of concern: A modeling approach

The emergence of SARS-CoV-2 variants of concern (VOCs) punctuated the dynamics of the COVID-19 pandemic in multiple occasions. The stages subsequent to their identification have been particularly challenging due to the hurdles associated with a prompt assessment of transmissibility and immune evasion characteristics of the newly emerged VOC. Here, we retrospectively analyze the performance of a modeling strategy developed to evaluate, in real-time, the risks posed by the Alpha and Omicron VOC soon after their emergence. Our approach utilized multi-strain, stochastic, compartmental models enriched with demographic information, age-specific contact patterns, the influence of non-pharmaceutical interventions, and the trajectory of vaccine distribution. The models' preliminary assessment about Omicron's transmissibility and immune evasion closely match later findings. Additionally, analyses based on data collected since our initial assessments demonstrate the retrospective accuracy of our real-time projections in capturing the emergence and subsequent dominance of the Alpha VOC in seven European countries and the Omicron VOC in South Africa. This study shows the value of relatively simple epidemic models in assessing the impact of emerging VOCs in real time, the importance of timely and accurate data, and the need for regular evaluation of these methodologies as we prepare for future global health crises.

Policy options for sustainable access to off-patent antibiotics in Europe

Securing sustainable access to existing antibiotics optimises agent choice for individual treatments and is crucial to curb antibiotic resistance. Access to antibiotics is often restricted in many countries, due to general market unavailability or episodic shortages. This article outlines key policy options to maintain availability of existing antibiotics and enhance antibiotic supply chain resilience focusing on the perspectives of European Union (EU) and European Economic Area (EEA) institutions and member states.

A comparative analysis of supply chain factors impacting COVID-19 vaccine security in high-income countries (HICs) and low-income and middle-income countries (LMICs)

INTRODUCTION

The COVID-19 pandemic focused attention on the importance of vaccine security to national security. Demand for vaccines far exceeded supply when the first COVID-19 vaccines were released. Growing data suggest a non-perfect correlation among vaccine development, production, purchases, deliveries and vaccination rates. As such, the best approach to strengthening vaccine security remains unclear. In this study, we use an operations research/operations management framework to characterise the relationship between vaccine security and key supply chain predictor variables in high-income countries (HICs) and low-income and middle-income countries (LMICs).

METHODS

We performed a comparative analysis of vaccine security against eight supply chain variables in a purposive sample of five HICs and five LMICs during the early phase of the pandemic (31 March 2021 and 30 April 2021). All data were obtained from publicly available databases. We used descriptive statistics to characterise our data, basic statistics to compare data and scatter plots to visualise relationships.

RESULTS

Our data show greater vaccine security in HICs compared with LMICs (32.2% difference in April 2021; 95% CI 4.2% to 60.3%, p=0.03). We report a significant difference between HICs and LMICs in only two of the eight predictor variables studied. Interestingly, we observed large variation in vaccine security within HICs, with Canada, Israel and Japan being frequent outliers, and within LMICs, with India standing out.

CONCLUSION

Our data suggest a stronger relationship between vaccine security and 'downstream' supply chain variables compared with 'upstream' variables. However, multiple outliers and the lack of an even stronger relationship suggests that there is no magic bullet for vaccine security. To boost vaccine resilience, countries must be well governed and strategically reinforce deficient aspects of their supply chains. Modest strength in multiple domains may be the best approach to counteracting the effect of an unfamiliar, novel pathogen.

The burden of COVID-19 in Latin American and Caribbean countries: an analysis based on the Global Burden of Disease Study 2021

OBJECTIVES

The coronavirus disease 2019 (COVID-19) pandemic has had a profound impact on the countries of Latin America and the Caribbean. This study aims to summarise key findings from the Global Burden of Disease (GBD) 2021 in the region. We also explore disparities in burden rates and the relationship with the Socio-demographic Index (SDI).

STUDY DESIGN

A cross-sectional analysis of GBD 2021 results was conducted.

METHODS

We obtained the disability-adjusted life years (DALYs) due to COVID-19 for 20 countries, analysing number- and age-adjusted rates. Spearman's correlation (rho) and 95% confidence intervals (CIs) assessed the SDI-DALY rates relationship.

RESULTS

COVID-19 was the leading cause disease burden in the region, with 20,437,321 DALYs in 2020 and 31,525,824 in 2021. Premature mortality (years of life lost) accounted for over 95%. Disparities existed across sexes, age groups, and countries, with Bolivia and Peru having the highest rates. A significant 2021 correlation was found (rho = -0.55, 95% CI: -0.90 to 0.19; P = 0.013) but not in 2020 (rho = -0.40, 95% CI: -0.75 to 0.05; P = 0.078).

CONCLUSIONS

COVID-19 posed a significant burden in Latin America and the Caribbean, emphasising the need for targeted interventions, especially in socioeconomically disadvantaged regions.

Global landscape of COVID-19 vaccination programmes for older adults: a descriptive study

BACKGROUND

To minimise severe cases and deaths from COVID-19 among high-risk populations such as older adults (aged 60 years and older), it is crucial to monitor and update vaccination strategies. In this study, we aim to provide a global profile of the current COVID-19 vaccination programmes for older adults, including vaccination policies, coverage rates, and vaccine demand.

METHODS

We used publicly available data on the COVID-19 vaccines used, vaccination schedules, indicated age groups, and age-specific country-level vaccine coverage, updated through to July 20, 2024. Data on vaccination policy were extracted from publicly available sources in the following priority: (1) official sources (ie, government websites, health department websites, and official reports); (2) resources integrated by institutions or organisations (ie, European Center for Disease Prevention and Control, Africa Center for Disease Prevention and Control, and COVAX); and (3) cross-validated news and media reports derived from government or health department sources. We estimated coverage gaps to achievement of two specific objectives: (1) immunising 100% of older adults with primary series and a booster dose, as per WHO's goal; and (2) surpassing WHO's goal by administering one extra booster dose to 80% of older adults or achieving 80% coverage of a 2023-24 series vaccine.

FINDINGS

192 countries reported their use of COVID-19 vaccines for older people, of which 71 vaccine products have been used for older adults and 79 countries have deployed 22 vaccines containing components against variants of concern; 122 countries offered a second booster dose or a special booster dose, while others used only primary series or one booster dose. 96 countries prioritised older people for vaccination. Among countries with available data, the median proportion of individuals completing a primary series was 81% (IQR 58·3-92·0), for a first booster was 53% (14·1-81·7), for a second booster was 44·3% (13·5-69·7), and for a 2023-24 series vaccination was 23·6% (6·6-52·4), with large differences by region. Coverage of the second booster and the 2023-24 series was lower in individuals aged 60-70 years than in older age groups. To achieve the WHO target of 100% coverage for older populations with primary series and a booster dose, 1·01 doses per person are required, and to attain an 80% coverage for a second booster or 2023-24 series, surpassing WHO's goal, 1·43 doses per person are required.

INTERPRETATION

Progress of COVID-19 vaccination programmes for older adults is uneven across countries, emphasising an ongoing challenge to achieve vaccine equity for this high-risk age group. Therefore, it is essential to establish robust and timely vaccination surveillance systems, especially to facilitate data-driven policies that promote COVID-19 vaccination campaigns worldwide.

FUNDING

Key Program of the National Natural Science Foundation of China.

Generalized contact matrices allow integrating socioeconomic variables into epidemic models

Variables related to socioeconomic status (SES), including income, ethnicity, and education, shape contact structures and affect the spread of infectious diseases. However, these factors are often overlooked in epidemic models, which typically stratify social contacts by age and interaction contexts. Here, we introduce and study generalized contact matrices that stratify contacts across multiple dimensions. We demonstrate a lower-bound theorem proving that disregarding additional dimensions, besides age and context, might lead to an underestimation of the basic reproductive number. By using SES variables in both synthetic and empirical data, we illustrate how generalized contact matrices enhance epidemic models, capturing variations in behaviors such as heterogeneous levels of adherence to nonpharmaceutical interventions among demographic groups. Moreover, we highlight the importance of integrating SES traits into epidemic models, as neglecting them might lead to substantial misrepresentation of epidemic outcomes and dynamics. Our research contributes to the efforts aiming at incorporating socioeconomic and other dimensions into epidemic modeling.

Crossing the Equity Chasm: Addressing a Second Valley of Death in Biomedical Innovation

This Viewpoint discusses how medical innovation often does not reach vulnerable populations, a lack that results in disparities in morbidity and mortality globally.

SARS-CoV-2 correlates of protection from infection against variants of concern

Serum neutralizing antibodies (nAbs) induced by vaccination have been linked to protection against symptomatic and severe coronavirus disease 2019. However, much less is known about the efficacy of nAbs in preventing the acquisition of infection, especially in the context of natural immunity and against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immune-escape variants. Here we conducted mediation analysis to assess serum nAbs induced by prior SARS-CoV-2 infections as potential correlates of protection against Delta and Omicron infections, in rural and urban household cohorts in South Africa. We find that, in the Delta wave, D614G nAbs mediate 37% (95% confidence interval: 34-40%) of the total protection against infection conferred by prior exposure to SARS-CoV-2, and that protection decreases with waning immunity. In contrast, Omicron BA.1 nAbs mediate 11% (95% confidence interval: 9-12%) of the total protection against Omicron BA.1 or BA.2 infections, due to Omicron's neutralization escape. These findings underscore that correlates of protection mediated through nAbs are variant specific, and that boosting of nAbs against circulating variants might restore or confer immune protection lost due to nAb waning and/or immune escape. However, the majority of immune protection against SARS-CoV-2 conferred by natural infection cannot be fully explained by serum nAbs alone. Measuring these and other immune markers including T cell responses, both in the serum and in other compartments such as the nasal mucosa, may be required to comprehensively understand and predict immune protection against SARS-CoV-2.

Pandemic burden in low-income settings and impact of limited and delayed interventions: A granular modelling analysis of COVID-19 in Kabwe, Zambia

OBJECTIVES

Pandemic response in low-income countries (LICs) or settings often suffers from scarce epidemic surveillance and constrained mitigation capacity. The drivers of pandemic burden in such settings, and the impact of limited and delayed interventions remain poorly understood.

METHODS

We analysed COVID-19 seroprevalence and all-cause excess deaths data from the peri-urban district of Kabwe, Zambia between March 2020 and September 2021 with a novel mathematical model. Data encompassed three consecutive waves caused by the wild-type, Beta and Delta variants.

RESULTS

Across all three waves, we estimated a high cumulative attack rate, with 78% (95% credible interval [CrI] 71-85) of the population infected, and a high all-cause excess mortality, at 402 (95% CrI 277-473) deaths per 100,000 people. Ambitiously improving health care to a capacity similar to that in high-income settings could have averted up to 46% (95% CrI 41-53) of accrued excess deaths, if implemented from June 2020 onward. An early and accelerated vaccination rollout could have achieved the highest reductions in deaths. Had vaccination started as in some high-income settings in December 2020 and with the same daily capacity (doses per 100 population), up to 68% (95% CrI 64-71) of accrued excess deaths could have been averted. Slower rollouts would have still averted 62% (95% CrI 58-68), 54% (95% CrI 49-61) or 26% (95% CrI 20-38) of excess deaths if matching the average vaccination capacity of upper-middle-, lower-middle- or LICs, respectively.

CONCLUSIONS

Robust quantitative analyses of pandemic data are of pressing need to inform future global pandemic preparedness commitments.

Social norms, vaccine confidence, and interpersonal communication as predictors of vaccination intentions: Findings from slum areas in Varanasi, India

In recent years, India has seen significant improvements in childhood immunization, but rates among the urban poor remain stagnant. Disruptions during COVID-19 pandemic have created further challenges. This paper focuses on how social norms, vaccine confidence, and interpersonal communication independently and jointly affect vaccine intentions among caregivers of infants living in six slum areas in Varanasi, India. Data for this study come from the baseline assessments conducted before implementing the Happy Baby Program, an intervention to improve vaccination attitudes and intentions. In-person interviews (N = 2,058) were conducted with caretakers of children up to two years old. Analyses showed that interpersonal communication about vaccines, descriptive norms, injunctive norms, and vaccine confidence were each associated with intentions to vaccinate in both a bivariate and, except for injunctive norms, a multivariate model. In addition, we found significant interactions among these variables, suggesting that the roles of interpersonal communication and vaccine confidence attenuated the relationship between social norms and vaccination intention. Overall, our model explained 46.2 % of the variance in vaccine intention. Given the strengths of the relationships observed in this study, intervention strategies should focus on enhancing social norms and vaccine confidence to promote vaccination.

The Improvement of Adaptive Immune Responses towards COVID-19 Following Diphtheria-Tetanus-Pertussis and SARS-CoV-2 Vaccinations in Indonesian Children: Exploring the Roles of Heterologous Immunity

BACKGROUND

Routine childhood vaccination, e.g., for diphtheria, tetanus, and pertussis (DTP), might provide additional protection against SARS-CoV-2 infection. This concept of heterologous immunity was explored in healthy children receiving both DTP and inactivated SARS-CoV-2 vaccines.

METHODS

A cross-sectional study was performed on 154 healthy children aged 6-8 years old in Jakarta, Indonesia. Their vaccination status for the DTP (including a diphtheria-tetanus booster vaccine at 5 years old) and CoronaVac (from 6 years old) vaccines were recorded. Peripheral blood samples were collected from all participants, in which anti-diphtheria toxoid IgG and anti-SARS-CoV-2 S-RBD antibodies and T cell-derived IFN-γ were measured.

RESULTS

The study participants with complete DTP vaccination had significantly higher titers of anti-diphtheria toxoid IgG than the ones without (median = 0.9349 versus 0.2113 IU/mL; p < 0.0001). Upon stratification based on DTP and CoronaVac vaccination statuses, the participants with complete DTP and CoronaVac vaccinations had the highest titer of anti-SARS-CoV-2 S-RBD antibodies (median = 1196 U/mL) and the highest concentration of SARS-CoV-2-specific T cell-derived IFN-γ (median = 560.9 mIU/mL) among all the groups.

CONCLUSIONS

Healthy children aged 6-8 years old with complete DTP and CoronaVac vaccinations exhibited stronger SARS-CoV-2-specific T cell immune responses. This might suggest an additional benefit of routine childhood vaccination in generating protection against novel pathogens, presumably via heterologous immunity.

Clinical profiles and mortality predictors of hospitalized patients with COVID-19 in Ethiopia

BACKGROUND

Studying the characteristics of hospitalized Coronavirus Disease 2019 (COVID-19) patients is vital for understanding the disease and preparing for future outbreaks. The aim of this study was to analyze and describe the clinical profiles and factors associated with mortality among COVID-19 patients admitted to Jimma Medical Center COVID-19 Treatment Center (JMC CTC) in Ethiopia.

METHODS

All confirmed COVID-19 patients admitted to JMC CTC between 17 April 2020 and 05 March 2022 were included in this study. Socio-demographic data, clinical information, and outcome variables were collected retrospectively from medical records and COVID-19 database at the hospital. Bivariable and multivariable analyses were performed to determine factors associated with COVID-19 severity and mortality. A P-value < 0.05 was considered statistically significant.

RESULTS

A total of 542 confirmed COVID-19 patients were admitted to JMC CTC, of which 322 (59.4%) were male. Their median age was 48 years (IQR 32-64). About 51% (n = 277) of them had severe COVID-19 upon admission. Patients with hypertension [AOR: 2.8 (95% CI: 1.02-7.7, p = 0.046)], diabetes [AOR: 8.8 (95% CI: 1.2-17.3, p = 0.039)], and underlying respiratory diseases [AOR: 18.8 (95% CI: 2.06-71.51, p = 0.009)] were more likely to present with severe COVID-19 cases. Overall, 129 (23.8%) died in the hospital. Death rate was higher among patients admitted with severe disease [AHR = 5.5 (3.07-9.9) p < 0.001)] and those with comorbidities such as hypertension [AHR = 3.5 (2.28-5.41), p < 0.001], underlying respiratory disease [AHR = 3.4 (1.97-5.94), p < 0.001], cardiovascular disease (CVDs) [AHR = 2.8 (1.73-4.55), p < 0.001], and kidney diseases [AHR = 3.7 (2.3-5.96), p < 0.001].

CONCLUSION

About half of COVID-19 cases admitted to the hospital had severe disease upon admission. Comorbidities such as hypertension, diabetes, and respiratory diseases were linked to severe illness. COVID-19 admissions were associated with high inpatient mortality, particularly among those with severe disease and comorbidities.

Pursuing equitable access to vaccines for the next epidemic

To mitigate the pandemic stemming from COVID-19, numerous nations have initiated extensive vaccination campaigns for their citizens since late 2020. While affluent countries have predominantly received vaccine allocations, fewer doses have been dispatched to nations with lower average incomes. This unequal distribution not only widens the disparity between wealthy and impoverished regions but also prolongs the pandemic, evident in the emergence of new viral variants. Our research delves into the correlation between the duration of the pandemic and the timing of vaccine distribution between two countries with migratory ties. By using a pair of coupled susceptible-infected-recovered-deceased models incorporating vaccination data, we demonstrate that timely sharing of vaccines benefits both nations, regardless of the presence of viral variants. This underscores that in the realm of vaccine distribution, self-interest and altruism are not mutually exclusive.

Effects of mobility, immunity and vaccination on SARS-CoV-2 transmission in the Dominican Republic: a modelling study

Background

COVID-19 dynamics are driven by a complex interplay of factors including population behaviour, new variants, vaccination and immunity from prior infections. We quantify drivers of SARS-CoV-2 transmission in the Dominican Republic, an upper-middle income country of 10.8 million people. We then assess the impact of the vaccination campaign implemented in February 2021, primarily using CoronaVac, in saving lives and averting hospitalisations.

Methods

We fit an age-structured, multi-variant transmission dynamic model to reported deaths, hospital bed occupancy, and seroprevalence data until December 2021, and simulate epidemic trajectories under different counterfactual scenarios.

Findings

We estimate that vaccination averted 7210 hospital admissions (95% credible interval, CrI: 6830-7600), 2180 intensive care unit admissions (95% CrI: 2080-2280) and 766 deaths (95% CrI: 694-859) in the first 6 months of the campaign. If no vaccination had occurred, we estimate that an additional decrease of 10-20% in population mobility would have been required to maintain equivalent death and hospitalisation outcomes. We also found that early vaccination with CoronaVac was preferable to delayed vaccination using a product with higher efficacy.

Interpretation

SARS-CoV-2 transmission dynamics in the Dominican Republic were driven by a substantial accumulation of immunity during the first two years of the pandemic but, despite this, vaccination was essential in enabling a return to pre-pandemic mobility levels without considerable additional morbidity and mortality.

Funding

Medical Research Council, Wellcome Trust, Royal Society, US CDC and Australian National Health and Medical Research Council.

Vaccine Hesitancy in Taiwan: Temporal, Multilayer Network Study of Echo Chambers Shaped by Influential Users

BACKGROUND

Vaccine hesitancy is a growing global health threat that is increasingly studied through the monitoring and analysis of social media platforms. One understudied area is the impact of echo chambers and influential users on disseminating vaccine information in social networks. Assessing the temporal development of echo chambers and the influence of key users on their growth provides valuable insights into effective communication strategies to prevent increases in vaccine hesitancy. This also aligns with the World Health Organization's (WHO) infodemiology research agenda, which aims to propose new methods for social listening.

OBJECTIVE

Using data from a Taiwanese forum, this study aims to examine how engagement patterns of influential users, both within and across different COVID-19 stances, contribute to the formation of echo chambers over time.

METHODS

Data for this study come from a Taiwanese forum called PTT. All vaccine-related posts on the "Gossiping" subforum were scraped from January 2021 to December 2022 using the keyword "vaccine." A multilayer network model was constructed to assess the existence of echo chambers. Each layer represents either provaccination, vaccine hesitant, or antivaccination posts based on specific criteria. Layer-level metrics, such as average diversity and Spearman rank correlations, were used to measure chambering. To understand the behavior of influential users-or key nodes-in the network, the activity of high-diversity and hardliner nodes was analyzed.

RESULTS

Overall, the provaccination and antivaccination layers are strongly polarized. This trend is temporal and becomes more apparent after November 2021. Diverse nodes primarily participate in discussions related to provaccination topics, both receiving comments and contributing to them. Interactions with the antivaccination layer are comparatively minimal, likely due to its smaller size, suggesting that the forum is a "healthy community." Overall, diverse nodes exhibit cross-cutting engagement. By contrast, hardliners in the vaccine hesitant and antivaccination layers are more active in commenting within their own communities. This trend is temporal, showing an increase during the Omicron outbreak. Hardliner activity potentially reinforces their stances over time. Thus, there are opposing forces of chambering and cross-cutting.

CONCLUSIONS

Efforts should be made to moderate hardliner and influential nodes in the antivaccination layer and to support provaccination users engaged in cross-cutting exchanges. There are several limitations to this study. One is the bias of the platform used, and another is the lack of a comprehensive definition of "influence." To address these issues, comparative studies across different platforms can be conducted, and various metrics of influence should be explored. Additionally, examining the impact of influential users on network structure and chambering through network simulations and regression analysis provides more robust insights. The study also lacks an explanation for the reasons behind chambering trends. Conducting content analysis can help to understand the nature of engagement and inform interventions to address echo chambers. These approaches align with and further the WHO infodemic research agenda.

Lessons from the COVID-19 Pandemic: Promoting Vaccination and Public Health Resilience, a Narrative Review

The COVID-19 pandemic has underscored the critical importance of adaptable and resilient public health systems capable of rapid response to emerging health crises. This paper synthesizes the lessons learned from the COVID-19 vaccination campaign and explores strategies to enhance vaccine uptake in the post-pandemic era. Key challenges identified include logistical, economic, sociocultural, and policy dimensions that impact vaccination efforts, particularly in low-resource settings. The analysis highlights the need for resilient supply chains, effective communication, community engagement, and equitable access to healthcare resources. The rapid development and deployment of mRNA vaccines exemplify the potential of innovative vaccine technologies, though public trust and acceptance remain crucial. Strategies such as partnerships with local leaders, tailored messaging, and integration of digital tools are essential for combating vaccine hesitancy. By applying these insights, future vaccination campaigns can be more efficient, equitable, and resilient, ultimately improving public health outcomes globally. This paper aims to inform policy and practice, ensuring that public health strategies are evidence based and context specific, thus better preparing for future health challenges.

Evolution of digital twins in precision health applications: a scoping review study

An increasing amount of research is incorporating the concept of Digital twin (DT) in biomedical and health care applications. This scoping review aims to summarize existing research and identify gaps in the development and use of DTs in the health care domain. The focus of this study lies on summarizing: the different types of DTs, the techniques employed in DT development, the DT applications in health care, and the data resources used for creating DTs. We identified fifty studies, which mainly focused on creating organ- (n=15) and patient-specific twins (n=30). The research predominantly centers on cardiology, endocrinology, orthopedics, and infectious diseases. Only a few studies used real-world datasets for developing their DTs. However, there remain unresolved questions and promising directions that require further exploration. This review provides valuable reference material and insights for researchers on DTs in health care and highlights gaps and unmet needs in this field.

COVID-19 Vaccination and Public Health: Addressing Global, Regional, and Within-Country Inequalities

The COVID-19 pandemic, with over 775 million cases and 7 million deaths by May 2024, has drastically impacted global public health and exacerbated existing healthcare inequalities. The swift development and distribution of COVID-19 vaccines have been critical in combating the virus, yet disparities in access to and administration of the vaccine have highlighted deep-seated inequities at global, regional, and national levels. Wealthier nations have benefited from early access to vaccines, while low- and middle-income countries (LMICs) have faced persistent shortages. Initiatives such as COVAX aimed to address these disparities, but challenges persist. Socioeconomic factors, education, ethnic identity, and the healthcare infrastructure play crucial roles in vaccine equity. For example, lower-income individuals often face barriers such as poor access to healthcare, misinformation, and logistical challenges, particularly in rural areas. Addressing these inequities requires a multifaceted approach, integrating national policies with local strategies to enhance vaccines' accessibility, counter misinformation, and ensure equitable distribution. Collaborative efforts at all levels are essential to promote vaccine equity and effectively control the pandemic, ensuring that all populations have fair access to life-saving vaccines. This review explores these complex issues, offering insights into the barriers and facilitators of vaccine equity and providing recommendations to promote more equitable and effective vaccination programs. With a focus on the different levels at which vaccination policies are planned and implemented, the text provides guidelines to steer vaccination strategies, emphasizing the role of international cooperation and local policy frameworks as keys to achieving equitable vaccination coverage.

COVID-19 Vaccine Hesitancy: Umbrella Review of Systematic Reviews and Meta-Analysis

BACKGROUND

The unprecedented emergence of the COVID-19 pandemic necessitated the development and global distribution of vaccines, making the understanding of global vaccine acceptance and hesitancy crucial to overcoming barriers to vaccination and achieving widespread immunization.

OBJECTIVE

This umbrella review synthesizes findings from systematic reviews and meta-analyses to provide insights into global perceptions on COVID-19 vaccine acceptance and hesitancy across diverse populations and regions.

METHODS

We conducted a literature search across major databases to identify systematic reviews and meta-analysis that reported COVID-19 vaccine acceptance and hesitancy. The AMSTAR-2 (A Measurement Tool to Assess Systematic Reviews) criteria were used to assess the methodological quality of included systematic reviews. Meta-analysis was performed using STATA 17 with a random effect model. The data synthesis is presented in a table format and via a narrative.

RESULTS

Our inclusion criteria were met by 78 meta-analyses published between 2021 and 2023. Our analysis revealed a moderate vaccine acceptance rate of 63% (95% CI 0.60%-0.67%) in the general population, with significant heterogeneity (I2 = 97.59%). Higher acceptance rates were observed among health care workers and individuals with chronic diseases, at 64% (95% CI 0.57%-0.71%) and 69% (95% CI 0.61%-0.76%), respectively. However, lower acceptance was noted among pregnant women, at 48% (95% CI 0.42%-0.53%), and parents consenting for their children, at 61.29% (95% CI 0.56%-0.67%). The pooled vaccine hesitancy rate was 32% (95% CI 0.25%-0.39%) in the general population. The quality assessment revealed 19 high-quality, 38 moderate-quality, 15 low-quality, and 6 critically low-quality meta-analyses.

CONCLUSIONS

This review revealed the presence of vaccine hesitancy globally, emphasizing the necessity for population-specific, culturally sensitive interventions and clear, credible information dissemination to foster vaccine acceptance. The observed disparities accentuate the need for continuous research to understand evolving vaccine perceptions and to address the unique concerns and needs of diverse populations, thereby aiding in the formulation of effective and inclusive vaccination strategies.

TRIAL REGISTRATION

PROSPERO CRD42023468363; https://tinyurl.com/2p9kv9cr.

Risk of COVID-19 death for people with a pre-existing cancer diagnosis prior to COVID-19-vaccination: A systematic review and meta-analysis

While previous reviews found a positive association between pre-existing cancer diagnosis and COVID-19-related death, most early studies did not distinguish long-term cancer survivors from those recently diagnosed/treated, nor adjust for important confounders including age. We aimed to consolidate higher-quality evidence on risk of COVID-19-related death for people with recent/active cancer (compared to people without) in the pre-COVID-19-vaccination period. We searched the WHO COVID-19 Global Research Database (20 December 2021), and Medline and Embase (10 May 2023). We included studies adjusting for age and sex, and providing details of cancer status. Risk-of-bias assessment was based on the Newcastle-Ottawa Scale. Pooled adjusted odds or risk ratios (aORs, aRRs) or hazard ratios (aHRs) and 95% confidence intervals (95% CIs) were calculated using generic inverse-variance random-effects models. Random-effects meta-regressions were used to assess associations between effect estimates and time since cancer diagnosis/treatment. Of 23 773 unique title/abstract records, 39 studies were eligible for inclusion (2 low, 17 moderate, 20 high risk of bias). Risk of COVID-19-related death was higher for people with active or recently diagnosed/treated cancer (general population: aOR = 1.48, 95% CI: 1.36-1.61, I2  = 0; people with COVID-19: aOR = 1.58, 95% CI: 1.41-1.77, I2  = 0.58; inpatients with COVID-19: aOR = 1.66, 95% CI: 1.34-2.06, I2  = 0.98). Risks were more elevated for lung (general population: aOR = 3.4, 95% CI: 2.4-4.7) and hematological cancers (general population: aOR = 2.13, 95% CI: 1.68-2.68, I2  = 0.43), and for metastatic cancers. Meta-regression suggested risk of COVID-19-related death decreased with time since diagnosis/treatment, for example, for any/solid cancers, fitted aOR = 1.55 (95% CI: 1.37-1.75) at 1 year and aOR = 0.98 (95% CI: 0.80-1.20) at 5 years post-cancer diagnosis/treatment. In conclusion, before COVID-19-vaccination, risk of COVID-19-related death was higher for people with recent cancer, with risk depending on cancer type and time since diagnosis/treatment.

Dynamic SARS-CoV-2 surveillance model combining seroprevalence and wastewater concentrations for post-vaccine disease burden estimates

BACKGROUND

Despite wide scale assessments, it remains unclear how large-scale severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination affected the wastewater concentration of the virus or the overall disease burden as measured by hospitalization rates.

METHODS

We used weekly SARS-CoV-2 wastewater concentration with a stratified random sampling of seroprevalence, and linked vaccination and hospitalization data, from April 2021-August 2021 in Jefferson County, Kentucky (USA). Our susceptible ( S ), vaccinated ( V ), variant-specific infected (I 1 andI 2 ), recovered ( R ), and seropositive ( T ) model ( S V I 2 R T ) tracked prevalence longitudinally. This was related to wastewater concentration.

RESULTS

Here we show the 64% county vaccination rate translate into about a 61% decrease in SARS-CoV-2 incidence. The estimated effect of SARS-CoV-2 Delta variant emergence is a 24-fold increase of infection counts, which correspond to an over 9-fold increase in wastewater concentration. Hospitalization burden and wastewater concentration have the strongest correlation (r = 0.95) at 1 week lag.

CONCLUSIONS

Our study underscores the importance of continuing environmental surveillance post-vaccine and provides a proof-of-concept for environmental epidemiology monitoring of infectious disease for future pandemic preparedness.

Jude COVID-19 Case Investigation and Contact Tracing Team, Gaur AH, Hakim H. Employee investigation and contact tracing program in a pediatric cancer hospital to mitigate the spread of COVID-19 among the workforce, patients, and caregivers

Background

Case investigations and contact tracing are essential disease control measures used by health departments. Early in the pandemic, they were seen as a key strategy to stop COVID-19 spread. The CDC urged rapid action to scale up and train a large workforce and collaborate across public and private agencies to halt COVID-19 transmission.

Methods

We developed a program for case investigation and contact tracing that followed CDC and local health guidelines, compliant with the Occupational Safety and Health Administration (OSHA) regulations and tailored to the needs and resources of our institution. Program staff were trained and assessed for competency before joining the program.

Results

From March 2020 to May 2021, we performed 838 COVID-19 case investigations, which led to 136 contacts. Most employees reported a known SARS-CoV-2 exposure from the community (n = 435) or household (n = 343). Only seven (5.1%) employees were determined as more likely than not to have SARS-CoV-2 infection related to workplace exposure, and when so, lapses in following the masking recommendations were identified. Between June 2021-February 2022, our program adjusted to the demand of the different waves, particularly omicron, by significantly reducing the amount of data collected. No transmission from employees to patients or caregivers was observed during this period.

Conclusion

Prompt implementation of case investigation and contact tracing is possible, and it effectively reduces workplace exposures. This approach can be adapted to suit the specific needs and requirements of various healthcare settings, particularly those serving the most vulnerable patient populations.

Stochastic dynamical analysis for the complex infectious disease model driven by multisource noises

This paper mainly studies the dynamical behavior of the infectious disease model affected by white noise and Lévy noise. First, a stochastic model of infectious disease with secondary vaccination affected by noises is established. Besides, the existence and uniqueness of the global positive solution for the stochastic model are proved based on stochastic differential equations and Lyapunov function, then the asymptotic behavior of the disease-free equilibrium point is studied. Moreover, the sufficient conditions for the extinction of the disease are obtained and the analysis showed that different noise intensity could affect the extinction of infectious disease on different degree. Finally, the theoretical results are verified by numerical simulation and some suggestions have been put forward on how to prevent the spread of diseases are presented.

Vaccine inequity: a threat to Africa's recovery from COVID-19

BACKGROUND

Vaccine inequity is a reality facing the Sub-Saharan Africa region as vaccine nationalism from high-income countries (HICs) leads to limited access to the lifesaving vaccines needed to end the pandemic. In Africa, a significant portion of the population has yet to be vaccinated against Covid-19; however, the barriers to accessing such vaccines, including capacity challenges, still persist despite the implementation of the COVAX facility meant to support the lower- and middle-income countries (LMICs) to boost vaccination.

METHODS

This study involved a systemic narrative review where literature search was conducted using the NCBI's PMC and BMC databases based on defined keywords. Three authors were involved in the literature search and consensus was applied to settle disagreements and validate the findings.

RESULTS

In this systematic narrative review, we report that vaccine nationalism remains a challenge for LMICs as HICs still hoard vaccines and even bypass COVAX to procure doses directly from the manufacturers. Factors that promote vaccine hesitancy in Africa include misinformation regarding the Covid-19 vaccine, a lack of trust in politicians and the pharmaceutical industry, and concerns about vaccine safety and efficacy. The policies implemented to enhance vaccine coverage in Africa, such as mandates, community engagement, and partnerships, all seek to promote equity of vaccination and ending Covid-19.

CONCLUSION

Covid-19 vaccine inequity persists and contributes to prolonged pandemic in LMICs. In response, African governments have taken certain measures to enhance vaccine uptake but more needs to be done to address resistance to vaccines.

Safety of Janssen Ad26.COV.S and Astra Zeneca AZD1222 COVID-19 Vaccines among Mobile Phone Users in Malawi: Findings from a National Mobile-Based Syndromic Surveillance Survey, July 2021 to December 2021

The safety profiles of the Ad26.COV2.S and AZD1222 COVID-19 vaccines have not been described in the general population in Malawi. We present self-reported adverse events (AE) following the receipt of these vaccines in Malawi as part of a national syndromic surveillance survey. We conducted phone-based syndromic surveillance surveys among adults (≥18 years) with verbal consent. We used secure tablets through random digit dialing to select mobile phone numbers and collected data electronically. Survey questions included whether the respondent had received the COVID-19 vaccines, whether they had experienced any AE following vaccination, and the severity of the AE. We used multivariable analysis to identify factors associated with self-reported AE post-COVID-19 vaccination. A total of 11,924 (36.0%) out of 33,150 respondents reported receiving at least one dose of either Ad26.COV2.S or AZD1222 between July-December 2021; of those, 65.1% were female. About 49.2% of the vaccine recipients reported at least one AE, 90.6% of which were mild, and 2.6% were severe. Higher education level and concern about the safety of COVID-19 vaccines were associated with AE self-report (Adjusted Odds Ratio [AOR] 2.63 [95% CI 1.96-3.53] and 1.44, [95% CI 1.30-1.61], respectively), while male gender and older age were associated with reduced likelihood of AE self-report (AORs 0.81, [95% CI 0.75-0.88], 0.62 [95% CI 0.50-0.77], respectively). Ad26.COV2.S and AZD1222 vaccines are well-tolerated, with primarily mild and few severe AE among adults living in Malawi. Self-reporting of AE following COVID-19 vaccination is associated with gender, age, education, and concern about the safety of the vaccines. Recognizing these associations is key when designing and implementing COVID-19 vaccination communication messages to increase vaccination coverage.

Long-term vaccination strategies to mitigate the impact of SARS-CoV-2 transmission: A modelling study

BACKGROUND

Vaccines have reduced severe disease and death from Coronavirus Disease 2019 (COVID-19). However, with evidence of waning efficacy coupled with continued evolution of the virus, health programmes need to evaluate the requirement for regular booster doses, considering their impact and cost-effectiveness in the face of ongoing transmission and substantial infection-induced immunity.

METHODS AND FINDINGS

We developed a combined immunological-transmission model parameterised with data on transmissibility, severity, and vaccine effectiveness. We simulated Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) transmission and vaccine rollout in characteristic global settings with different population age-structures, contact patterns, health system capacities, prior transmission, and vaccine uptake. We quantified the impact of future vaccine booster dose strategies with both ancestral and variant-adapted vaccine products, while considering the potential future emergence of new variants with modified transmission, immune escape, and severity properties. We found that regular boosting of the oldest age group (75+) is an efficient strategy, although large numbers of hospitalisations and deaths could be averted by extending vaccination to younger age groups. In countries with low vaccine coverage and high infection-derived immunity, boosting older at-risk groups was more effective than continuing primary vaccination into younger ages in our model. Our study is limited by uncertainty in key parameters, including the long-term durability of vaccine and infection-induced immunity as well as uncertainty in the future evolution of the virus.

CONCLUSIONS

Our modelling suggests that regular boosting of the high-risk population remains an important tool to reduce morbidity and mortality from current and future SARS-CoV-2 variants. Our results suggest that focusing vaccination in the highest-risk cohorts will be the most efficient (and hence cost-effective) strategy to reduce morbidity and mortality.

CO-Sprout-A Pilot Double-Blinded Placebo-Controlled Randomised Trial of Broccoli Sprout Powder Supplementation for Pregnant Women with COVID-19 on the Duration of COVID-19-Associated Symptoms: Study Protocol

Since its discovery in late 2019, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been estimated to be responsible for at least 769.3 million infections and over 6.95 million deaths. Despite significant global vaccination efforts, there are limited therapies that are considered safe and effective for use in the management of COVID-19 during pregnancy despite the common knowledge that pregnant patients have a much higher risk of adverse outcomes. A bioactive compound found in broccoli sprout-sulforaphane-is a potent inducer of phase-II detoxification enzymes promoting a series of potentially beneficial effects notably as an antioxidant, anti-inflammatory, and anti-viral. A pilot, double-blinded, placebo-controlled randomised trial is to be conducted in Melbourne, Australia, across both public and private hospital sectors. We will assess a commercially available broccoli sprout extract in pregnant women between 20+0 and 36+0 weeks gestation with SARS-CoV-2 infection to investigate (i) the duration of COVID-19 associated symptoms, (ii) maternal and neonatal outcomes, and (iii) biomarkers of infection and inflammation. We plan to enrol 60 outpatient women with COVID-19 irrespective of vaccination status diagnosed by PCR swab or RAT (rapid antigen test) within five days and randomised to 14 days of oral broccoli sprout extract (42 mg of sulforaphane daily) or identical microcrystalline cellulose placebo. The primary outcome of this pilot trial will be to assess the feasibility of conducting a larger trial investigating the duration (days) of COVID-19-associated symptoms using a broccoli sprout supplement for COVID-19-affected pregnancies. Pregnant patients remain an at-risk group for severe disease following infection with SARS-CoV-2 and currently unclear consequences for the offspring. Therefore, this study will assess feasibility of using a broccoli sprout supplement, whilst providing important safety data for the use of sulforaphane in pregnancy.

Retrospective analysis of equity-based optimization for COVID-19 vaccine allocation

Marginalized racial and ethnic groups in the United States were disproportionally affected by the COVID-19 pandemic. To study these disparities, we construct an age-and-race-stratified mathematical model of SARS-CoV-2 transmission fitted to age-and-race-stratified data from 2020 in Oregon and analyze counterfactual vaccination strategies in early 2021. We consider two racial groups: non-Hispanic White persons and persons belonging to BIPOC groups (including non-Hispanic Black persons, non-Hispanic Asian persons, non-Hispanic American-Indian or Alaska-Native persons, and Hispanic or Latino persons). We allocate a limited amount of vaccine to minimize overall disease burden (deaths or years of life lost), inequity in disease outcomes between racial groups (measured with five different metrics), or both. We find that, when allocating small amounts of vaccine (10% coverage), there is a trade-off between minimizing disease burden and minimizing inequity. Older age groups, who are at a greater risk of severe disease and death, are prioritized when minimizing measures of disease burden, and younger BIPOC groups, who face the most inequities, are prioritized when minimizing measures of inequity. The allocation strategies that minimize combinations of measures can produce middle-ground solutions that similarly improve both disease burden and inequity, but the trade-off can only be mitigated by increasing the vaccine supply. With enough resources to vaccinate 20% of the population the trade-off lessens, and with 30% coverage, we can optimize both equity and mortality. Our goal is to provide a race-conscious framework to quantify and minimize inequity that can be used for future pandemics and other public health interventions.