Burden of four vaccine preventable diseases in older adults

The burden of influenza and the role of influenza vaccination in adults aged 50-64 years: A summary of available evidence

Influenza is a vaccine-preventable disease and a global public health problem. Although most national influenza vaccination recommendations focus on subjects aged ≥65 years, an extensive burden of influenza has also been reported in those aged ≥50 years and is exacerbated by immune system aging. The main purpose of this review is to provide an overview of the burden of influenza and its potential prevention within the 50-64 age-group. These subjects account for a large proportion of the workforce, and play a central economic and social role. Individuals aged 50-64 years had a 3-times higher rate of hospitalization and a 9-fold higher mortality rate attributable to influenza than those aged 18-49-years, generating higher influenza-related hospitalization costs. Available data suggest that including healthy subjects aged 50-64 years in influenza vaccination recommendations would allow a broader population to be reached, reducing the economic and social burden of influenza.

Willingness to get vaccinated against influenza, pneumococcal disease, pertussis, and herpes zoster - A pre-COVID-19 exploration among the older adult population

BACKGROUND

Older adults are at increased risk for adverse health outcomes when having an influenza, pneumococcal disease, pertussis, or herpes zoster infection. Despite the ability of vaccinations to prevent these adverse outcomes, vaccination coverage is low in the European Union. This study aimed to explore the sociodemographic, lifestyle, and health-related characteristics associated with vaccination willingness for these vaccine-preventable diseases.

METHODS

Cross-sectional data from wave 6 (years 2013-2017) of the population-based Doetinchem Cohort Study was analysed, with 3063 participants aged 46-86 years included. The outcome was the self-reported willingness to get vaccinated against influenza, pneumococcal disease, pertussis, and herpes zoster (willing, neutral, not willing). Multinomial logistic regression was used to investigate the socio-demographic, lifestyle and health characteristics associated with vaccination willingness.

RESULTS

For influenza 36 % was willing to get vaccinated, 35 % was neutral and 28 % was not willing to get vaccinated. The willingness to get vaccinated for the relatively unfamiliar vaccine-preventable diseases was lower: 26 % for pneumococcal disease (neutral: 50 %, not willing: 23 %), 26 % for pertussis (neutral 53 %, not willing: 22 %), and 23 % for herpes zoster (neutral 54 %, not willing: 24 %). A relative lower willingness was found among those 46-64 years old (compared to those 65 years or older). Women, having a high SES, being employed and having a good health were all associated with lower willingness to get vaccinated, which was the case for all vaccine-preventable diseases.

CONCLUSIONS

Older adults were generally more willing to get vaccinated against influenza than for the three less familiar diseases. Characteristics of those less willing may be used to improve strategies to increase vaccination coverage. Additional studies are needed to investigate the willingness to get vaccinated during and after the COVID-19 pandemic that may have changed the feel of urgency for vaccination.

Improving older adults' vaccination uptake: Are existing measures of vaccine hesitancy valid and reliable for older people?

We sought to establish whether two recently developed measures, the 5C scale and the Vaccination Attitudes Examination (VAX) were reliable and valid for use with older adults. A total of 372 UK-dwelling participants (65-92 years, M = 70.5 years, SD = 4.6) completed a cross-sectional survey measuring health and socio-demographic characteristics in relation to vaccine uptake for influenza, pneumococcal and shingles. The 5C and VAX scales were administered to test their reliability, validity and dimensionality. Both scales showed good internal reliability and convergent, discriminant and concurrent validity. Their factor structures were also confirmed, supporting their use with older adult populations.

Drivers of and barriers to routine adult vaccination: A systematic literature review

We performed a systematic literature review in PubMed and Embase (2016-2021) to investigate the drivers of and barriers to routine vaccination in adults aged 50 and older globally. A thematic assessment identified three categories across 61 publications: sociodemographic, health-related, and attitudinal. The most common sociodemographic determinants (factors identified in studies; n = 47) associated with vaccination uptake were economic status, age, education, and household composition, which had mixed effects on vaccine uptake. For health-related determinants (n = 27), individuals with comorbidities and health care consumption were the most common factors, both increased vaccine uptake. The most common attitudinal factors (n = 42) were self-efficacy, provider or other's recommendations, and vaccine-preventable disease awareness; across studies, all attitude factors had a positive effect, unlike the sociodemographic and health status categories. Findings suggest that patient and provider awareness and education campaigns are effective ways to increase uptake of routine vaccinations in older adults.

Influenza Vaccination Assessment according to a Value-Based Health Care Approach

Background: Seasonal influenza has a considerable public health impact, and vaccination is the key to preventing its consequences. Our aim was to describe how the value of influenza vaccination is addressed in the scientific literature considering a new value framework based on four pillars (personal, allocative, technical, and societal value). Methods: A systematic review was conducted by querying three databases. The analysis was performed on international studies focused on influenza vaccination value, and the four value pillars were taken into consideration for their description. Results: Overall, 40 studies were considered. Most of them focused on influenza vaccination in the general population (27.5%), emphasizing its value for all age groups. Most studies addressed technical value (70.4%), especially in terms of economic models and cost drivers to be considered for the economic evaluations of influenza vaccines, and societal value (63%), whereas few dealt with personal (37%) and allocative values (22.2%). Conclusions: The whole value of influenza vaccination is still not completely recognized. Knowledge and communication of the whole value of influenza vaccination is essential to guide value-based health policies. To achieve this goal, it is necessary to implement initiatives that involve all relevant stakeholders.

Infections and hospital bed-days among aging adults: A five-year retrospective study in a Belgian general hospital

Background

Infectious disease in aging adults (≥61 years) often occurs in combination with other health conditions leading to long hospital stays. Detailed studies on infection in aging adults investigating this problem are sparse.

Aim

To quantify the effect of primary and secondary diagnosed infections on hospitalization bed-days among aging adult patients.

Design

Retrospective patient-file study.

Setting

Ziekenhuis Netwerk Antwerpen (ZNA) Hospital, a 1,858-bed general hospital in Belgium, with 364 beds allocated to geriatric patients.

Data source

Database of hospitalized adult patients aged ≥61 years.

Methods

All adult patients aged ≥61 years hospitalized on two wards, Geriatrics and Pulmonology, from 2010 to 2014 were included. Primary diagnosed infections were defined as infections known at entry to be treated first. Secondary diagnosed infections included infections known at entry but treated in parallel to primary non-infectious causes of entry, infections unknown at entry, and hospital-acquired (nosocomial) infections. Data were analyzed by patient age, gender, year, ward type, bed-days of hospitalization, infection rates, and seasonality.

Results

There were 3,306 primary diagnosed infections (18%) and 14,758 secondary infections (82%) identified in the two wards combined (54.7% of all hospital stays at those 2 wards). Secondary diagnosed infections accounted for a significantly higher proportion of hospitalizations in both wards (+40% for Geriatric ward; +20% for Pulmonology ward; p < 0.001) and were associated with a significantly longer average hospital stay (+4 days for Geriatric ward; +5 days for Pulmonology ward; p < 0.001). Nosocomial infections (12% for Geriatric ward; 7% for Pulmonology ward) were associated with particularly high bed-days of hospitalization, at approximately +15 days and +12 days on Geriatric and Pulmonology wards, respectively. Both wards showed marked seasonality for respiratory infections with winter peaks.

Conclusion

Real-world data showed that secondary diagnosed infections in aging adults imposed a high burden on hospital care along with longer hospital stays. This hampered bed availability during peak seasons.

Descriptive Overview of Pertussis Epidemiology Among Older Adults in Europe During 2010–2020

Introduction

Following the introduction of pertussis vaccination during infancy, the age-related demographics of pertussis epidemiology have changed.

Methods

To better understand the pertussis burden (defined here as number of cases and/or incidence rate [IR]) among older adults (OA; at least 50 years of age) in Europe, we collected data on the reported number of cases and IR in this population in Denmark, England and Scotland, Finland, Germany, the Netherlands, Norway and Sweden from 2010 to 2020. Additionally, we collected contextual epidemiological information on surveillance systems, case definitions, laboratory diagnostics and vaccination approaches.

Results

We observed large heterogeneity in the burden among OA between countries: annual IRs ranged from 0.4 (England, 2010) to 54.5 (Norway, 2011) per 100,000 population; 9% (Denmark, 2010) to 45% (England, 2017) of all reported cases occurred in OA. No clear impact of changes in contextual epidemiological information or common trends between countries could be observed, highlighting the need for standardised pertussis surveillance programmes across Europe. The epidemiological trends observed in OA were similar to those observed in 0–4-year-olds.

Conclusion

This analysis showed that B. pertussis continues to circulate among OA in Europe, suggesting that current vaccination strategies are insufficient to decrease the disease burden in all age groups. This may indicate that improved monitoring of pertussis in OA and booster vaccination throughout adulthood are necessary to control the total pertussis burden.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-022-00668-y.

Whooping cough is an infectious, vaccine-preventable disease that is primarily serious in unvaccinated infants but can also affect adults (at least 50 years old). While vaccination is well established in children, many countries do not routinely vaccinate older adults. Moreover, whooping cough infections in older adults can be difficult to identify for healthcare professionals because of the atypical and mild nature of symptoms. Consequently, the extent of whooping cough occurrence in this population is underestimated. To better understand the extent of disease occurrence, we studied whooping cough infections in Denmark, England and Scotland, Finland, Germany, the Netherlands, Norway and Sweden from 2010 to 2020. Our study was based on the number of laboratory-confirmed cases reported to relevant institutions. We also assessed whether we could identify links between disease occurrence among older adults and contextual epidemiological information, such as disease monitoring systems, methods used for laboratory confirmation, vaccination schedules and vaccination coverage rates. Our study confirmed that whooping cough affects older adults and disease occurrence follows similar trends to those in 0- to 4-year-old children. Because the contextual epidemiological information differed over time and between countries, we could not establish links with disease occurrence in older adults. These data may provide further evidence to authorities that whooping cough among older adults would be better controlled and its burden more accurately estimated with a reinforced comprehensive approach around vaccination and monitoring. Because adults can also infect children who are not yet fully vaccinated, such an approach might help further control the disease in children.

Trends in Adult and Elderly Vaccination: Focus on Vaccination Practices in Tunisia and Morocco

Vaccine preventable diseases (VPDs) are a prevailing concern among the adult population, despite availability of vaccines. Unlike pediatric vaccination programs, adult vaccination programs lack the required reach, initiative, and awareness. Clinical studies and real-world data have proven that vaccines effectively reduce the disease burden of VPDs and increase life expectancy. In Tunisia and Morocco, the national immunization program (NIP) focuses more on pediatric vaccination and have limited vaccination programs for adults. However, some vaccination campaigns targeting adults are organized. For example, influenza vaccination campaigns prioritizing at risk adults which includes healthcare professionals, elderly, and patients with comorbidities. Women of childbearing age who have never been vaccinated or whose information is uncertain are recommended to receive tetanus vaccination. Tunisia NIP recommends rubella vaccine mainly for women of childbearing age, while in Morocco, national vaccination campaigns were organized for girls and women (up to 24 years of age) to eliminate rubella. Further, travelers from both countries are recommended to follow all requirements and recommendations in the travel destination. The objective of this manuscript is to provide an overview of the global disease burden of common VPDs including (but not limited to) meningococcal diseases, pneumococcal diseases, hepatitis, and influenza. The review also provides an overview of clinical data and guidelines/recommendations on adult vaccination practices, with special focus on Tunisia and Morocco. Some European and North American countries have concrete recommendations and strategies for adult vaccination to keep the VPDs in check. In Morocco and Tunisia, although, there are sporadic adult vaccination initiatives, the efforts still need upscaling and endorsements to boost vaccination awareness and uptake. There is a need to strengthen strategies in both countries to understand the disease burden and spread awareness. Additional studies are needed to generate economic evidence to support cost-effectiveness of vaccines. Integration of private and public healthcare systems may further improve vaccination uptake in adults.

Incidence trend and disease burden of seven vaccine-preventable diseases in Shandong province, China, 2013-2017: Findings from a population-based observational study

Introduction

Although vaccines provide a cost-effective solution to vaccine-preventable diseases (VPDs), the disease burden of VPDs is still very high in most parts of the world.

Methods

A population-based observational study was conducted in Shandong province, China, from 2013 to 2017, giving an insight into the epidemiological characteristics and disease burden of seven VPDs. The incidence trend was estimated using the Poisson regression model. The disease burden was calculated using the disability-adjusted life years (DALYs).

Results

Most VPDs included in the China’s National Immunization Program had higher incidence density (ID) in inland cities. The ID of mumps decreased significantly, while herpes zoster increased (both P < 0.05). The top three causes of the disease burden as assessed with DALYs included tuberculosis, herpes zoster, and hepatitis B, with the rates of 72.21, 59.99, and 52.10 DALYs/100 000, respectively. The disease burden of influenza and herpes zoster were relatively high in people aged > 50 years, while highest DALYs of hepatitis B were found in young adults.

Conclusion

Inequalities in the vaccine coverage by geography, socio-economic status, and targeted population contribute to the increasing incidence and high burden of VPDs and call for renewed and sustained immunization strategies in China.

Lot-to-lot consistency, safety, tolerability, and immunogenicity of V114, a 15-valent pneumococcal conjugate vaccine, in healthy adults aged ≥50 years: A randomized phase 3 trial (PNEU-TRUE)

BACKGROUND

Older adults are at risk of pneumococcal disease and associated morbidity and mortality. This phase 3 study (V114-020) assessed lot-to-lot consistency across safety and immunogenicity outcomes for V114, a 15-valent pneumococcal conjugate vaccine (PCV), in healthy adults aged ≥ 50 years.

METHODS

Adults were randomized in a 3:3:3:1 ratio to receive a single dose of one of three lots of V114 or 13-valent PCV (PCV13), stratified by age (50-64 years, 65-74 years, and ≥ 75 years). Serotype-specific opsonophagocytic activity (OPA) and immunoglobulin G (IgG) antibodies were evaluated at baseline (Day 1) and 30 days post-vaccination. Non-serious and serious adverse events (AEs) were evaluated post-vaccination through 14 days and Month 6, respectively.

RESULTS

Of 2340 participants enrolled, 2282 (97.5%) completed the study. Proportions of participants experiencing ≥ 1 AE were 81.0%, 77.4%, and 78.0% for V114 lots 1, 2, and 3, respectively. Comparison of V114 combined lots with PCV13 showed that proportions of participants experiencing AEs, solicited AEs, and serious AEs were comparable for both vaccines, with the exception of injection-site pain (more frequently reported with V114). OPA geometric mean titers (GMTs) and IgG geometric mean concentrations (GMCs) at 30 days post-vaccination were comparable across V114 lots, and all lots met predefined equivalence criteria for all 15 vaccine serotypes (lower and upper limits of the 95% confidence intervals of serotype-specific OPA GMT ratios for all possible pairwise comparisons across the three lots were within the equivalence margin of 0.5-2.0). Serotype-specific OPA GMTs and IgG GMCs were comparable in the V114 combined lots and PCV13 groups for the 13 shared serotypes and higher in the V114 group for serotypes unique to V114 (22F and 33F).

CONCLUSIONS

V114 is well tolerated with a consistent safety profile and immune response across manufacturing lots.

CLINICAL TRIALS REGISTRATION

NCT03950856 (www.clinicaltrials.gov); 2018-004266-33 (EudraCT).

Safety, tolerability, and immunogenicity of V114, a 15-valent pneumococcal conjugate vaccine, administered concomitantly with influenza vaccine in healthy adults aged ≥50 years: a randomized phase 3 trial (PNEU-FLU)

Streptococcus pneumoniae and influenza viruses are associated with significant morbidity and mortality in older adults. Concomitant vaccination against these agents reduces hospitalization and mortality rates. This phase 3 trial evaluated safety, tolerability, and immunogenicity of concomitant and non-concomitant administration of V114, a 15-valent pneumococcal conjugate vaccine containing serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19F, 19A, 22F, 23F, 33F, and quadrivalent inactivated influenza vaccine (QIV), in healthy adults aged ≥50 years. Participants (N = 1,200) were randomized 1:1 to receive either V114 administered concomitantly with QIV (concomitant group) or QIV plus placebo (non-concomitant group) on Day 1, followed by placebo (concomitant group) or V114 (non-concomitant group) 30 days later. Randomization was stratified by age and history of pneumococcal polysaccharide vaccine receipt. Overall, 426 (71.0%) and 438 (73.5%) participants in the concomitant and non-concomitant groups experienced solicited injection-site adverse events (AEs); 278 (46.3%) and 300 (50.3%) reported solicited systemic AEs. Most solicited AEs were mild or moderate in severity and of short duration. Non-inferiority for pneumococcal- and influenza-specific antibody responses (lower bound 95% confidence interval of opsonophagocytic activity [OPA] and hemagglutination inhibition geometric mean titers [GMTs] ratios ≥0.5) was demonstrated for concomitant versus non-concomitant administration for all 15 pneumococcal serotypes and all four influenza strains. Consistent with previous studies, a trend was observed toward lower pneumococcal OPA GMTs in the concomitant versus the non-concomitant group. V114 administered concomitantly with QIV is generally well tolerated and immunologically non-inferior to non-concomitant administration, supporting coadministration of both vaccines.

Cold Chain Management by Healthcare Providers at a District in Ghana: A Mixed Methods Study

Background

Despite the relevance of cold chain management in maintaining the potency of vaccines, gaps still exist in the ability of healthcare practitioners to maintain the cold chain system effectively. Thus, the current study sought to assess healthcare providers' knowledge, attitudes, practices, and challenges regarding cold chain management.

Methods

A concurrent mixed methods study was conducted at twelve facilities in the Sekyere Central District of Ghana. Eighty-six (86) participants took part in a survey that assessed their “cold chain management” knowledge and attitudes. Twelve (12) cold chain sites within the district were also observed in respect of their cold chain management practices. Eleven key informants were additionally interviewed to explore their challenges on cold chain management. Quantitative data were analyzed using descriptive (frequencies, percentages, means, standard deviations, ranges) and inferential statistics (Spearman's rho correlation). Qualitative data were inductively analyzed into themes which described participants' challenges on cold chain management.

Results

Majority of the participants scored ≥70% on knowledge (68.6%) and attitudes (67.4%) toward cold chain management. However, there was a very weak positive and statistically insignificant relationship between participant's knowledge and attitudes toward cold chain management (r = 0.109, p = 0.317). Regarding cold chain management practices, majority of the facilities had their vaccine vial monitors attached to the vaccines (8/12, 66.7%), had functional fridge tags (8/12, 66.7%), and an appropriate refrigerator to store vaccines (7/12, 58.3%). However, the study observed that 91.7% (11/12) of the facilities did not have policies and guidelines on cold chain management while all 12 facilities (100%) did not have a contingency plan in place for equipment. With regards to the cold chain management challenges, participants raised concerns about inadequate personnel, erratic power supply, logistical constraints, and transportation difficulties.

Conclusion

Although majority of the participants had good knowledge and attitude towards cold chain management, there was a weak association between them. This implies that good knowledge may not necessarily influence good attitudes towards cold chain management and vice versa. The extent to which facilities support cold chain management practices was suboptimal. Participants encountered a number of challenges which prevented them from managing the vaccine cold chain system effectively. We recommend continual professional education for cold chain practitioners, provision of adequate human and material resources for cold chain management, and enhanced monitoring and evaluation of cold chain activities. Future studies should quantitatively measure individual participants' knowledge, attitudes, practices, and challenges on cold chain management so that we can establish the relationships that exist between these components.

The estimated burden of 15 vaccine-preventable diseases from 2008 to 2020 in Japan: A transition by the COVID-19 pandemic

BACKGROUND

Evaluating the national burdens across multiple vaccine-preventable diseases (VPDs) can be informative to identify the areas for improvements in the national immunization program.

METHODS

The annual burden of diseases from 2008 to 2020 in Japan were calculated with the incidence- and pathogen-based approach for the 15 VPDs (hepatitis B virus infection, human papillomavirus (HPV), influenza, invasive pneumococcal disease, invasive Haemophilus influenzae type b (Hib) disease, invasive meningococcal disease, Japanese encephalitis, measles, mumps, pertussis, rotavirus, rubella, tetanus, tuberculosis and varicella), using disability-adjusted life year (DALY).

RESULTS

The average annual burden between 2008 and 2020 is the highest in influenza (114,129 DALY/year), followed by HPV infection, hepatitis B virus infection, tuberculosis and mumps (109,782, 69,883, 23,855 and 5693 DALY/year). In the pre-COVID-19 period (2008-2019), the decreasing trend of burden was observed in hepatitis B virus infection, invasive pneumococcal disease, invasive Hib disease, tuberculosis and varicella. HPV infection is the only VPD which had more than 100,000 DALY/year for all years during the study period. In 2020, the estimated annual burdens are decreased in influenza (71%), invasive pneumococcal disease (51%), invasive Hib diseases (54%), invasive meningococcal disease (64%), measles (98%), mumps (47%) pertussis (83%), rotavirus infection (95%), rubella (94%) and varicella (35%) compared with those in 2019.

CONCLUSIONS

The study demonstrated decreasing trends of burdens for some VPDs, while a persistently high burden has been observed for other VPDs, including HPV infection. The COVID-19 pandemic has caused dramatic reductions in the burdens of many VPDs in 2020.

European data sources for computing burden of (potential) vaccine-preventable diseases in ageing adults

BACKGROUND

To guide decision-making on immunisation programmes for ageing adults in Europe, one of the aims of the Vaccines and InfecTious diseases in the Ageing popuLation (IMI2-VITAL) project is to assess the burden of disease (BoD) of (potentially) vaccine-preventable diseases ((P)VPD). We aimed to identify the available data sources to calculate the BoD of (P)VPD in participating VITAL countries and to pinpoint data gaps. Based on epidemiological criteria and vaccine availability, we prioritized (P) VPD caused by Extra-intestinal pathogenic Escherichia coli (ExPEC), norovirus, respiratory syncytial virus, Staphylococcus aureus, and pneumococcal pneumonia.

METHODS

We conducted a survey on available data (e.g. incidence, mortality, disability-adjusted life years (DALY), quality-adjusted life years (QALY), sequelae, antimicrobial resistance (AMR), etc.) among national experts from European countries, and carried out five pathogen-specific literature reviews by searching MEDLINE for peer-reviewed publications published between 2009 and 2019.

RESULTS

Morbidity and mortality data were generally available for all five diseases, while summary BoD estimates were mostly lacking. Available data were not always stratified by age and risk group, which is especially important when calculating BoD for ageing adults. AMR data were available in several countries for S. aureus and ExPEC.

CONCLUSION

This study provides an exhaustive overview of the available data sources and data gaps for the estimation of BoD of five (P) VPD in ageing adults in the EU/EAA, which is useful to guide pathogen-specific BoD studies and contribute to calculation of (P)VPDs BoD.

Immunogenicity following revaccination or sequential vaccination with 23-valent pneumococcal polysaccharide vaccine (PPSV23) in older adults and those at increased risk of pneumococcal disease: a review of the literature

Introduction: Immunogenicity studies evaluating sequential administration of pneumococcal conjugate vaccine (PCV) followed by 23-valent pneumococcal polysaccharide vaccine (PPSV23) or revaccination with PPSV23 have raised concerns that PPSV23 may not elicit higher antibody levels than those measured following PCV or first PPSV23 dose.Areas covered: Recent literature was evaluated for evidence of blunted immune response (hyporesponsiveness), focusing on studies using adequate intervals between doses in accordance with vaccination recommendations. In eight of nine studies that evaluated revaccination with PPSV23 at an interval of ≥5 years after the previous dose, immunoglobulin G geometric mean concentrations and/or opsonophagocytic assay geometric mean titers for most serotypes increased from pre- to post-repeat vaccination and were comparable between repeat and primary vaccination groups post-vaccination. In seven studies in which PPSV23 was administered after PCVs (8 weeks to 1 year apart), responses to PPSV23 were comparable to those seen after initial PCV dose for shared vaccine serotypes. Studies in which PCVs were administered after PPSV23 were not evaluated.Expert opinion: Published data suggest immune responses following repeat vaccination with PPSV23, or sequential PCV/PPSV23 vaccination, are robust, without evidence of hyporesponsiveness. PPSV23 vaccination of at-risk adults is essential to ensure broad protection against all 23 vaccine serotypes.

Efficacy and effectiveness of a 23-valent polysaccharide vaccine against invasive and noninvasive pneumococcal disease and related outcomes: a review of available evidence

Introduction: Routine pneumococcal vaccination for adults aged ≥60 or ≥65 years and those with underlying at-risk and high-risk conditions is recommended in many countries. However, studies estimating the effectiveness of 23-valent pneumococcal polysaccharide vaccine (PPSV23) have revealed mixed results, partly due to variability in study design and endpoints used to assess outcomes.Areas covered: The authors conducted a literature review of independently randomized trials and real-world studies published from 2010 to 2020 that assessed the effectiveness and efficacy of PPSV23 against vaccine-type or any-serotype invasive and noninvasive pneumococcal disease in adults aged ≥60 years. The authors also evaluated differences in study design that may contribute to the heterogeneity of available evidence.Expert opinion: Policy decisions regarding the inclusion of vaccines into national immunization plans should consider study quality and limitations. This review shows that PPSV23 is effective against vaccine-type invasive pneumococcal disease and vaccine-type pneumococcal pneumonia and can lower the burden of vaccine-type pneumococcal pneumonia. PPSV23-conferred protection may be lower in adults aged ≥75 years, those with certain underlying conditions, and individuals who were vaccinated >5 years before disease onset. This is an important finding that supports the benefit of PPSV23 vaccination for older adults.

Influenza-like Illness Exacerbates Pneumococcal Carriage in Older Adults

BACKGROUND

In older adults pneumococcal disease is strongly associated with respiratory viral infections, but the impact of viruses on Streptococcus pneumoniae carriage prevalence and load remains poorly understood. Here, we investigated the effects of influenza-like illness (ILI) on pneumococcal carriage in community-dwelling older adults.

METHODS

We investigated the presence of pneumococcal DNA in saliva samples collected in the 2014/2015 influenza season from 232 individuals aged ≥60 years at ILI-onset, followed by sampling 2-3 weeks and 7-9 weeks after the first sample. We also sampled 194 age-matched controls twice 2-3 weeks apart. Pneumococcal DNA was detected with quantitative-PCRs targeting piaB and lytA genes in raw and in culture-enriched saliva. Bacterial and pneumococcal abundances were determined in raw saliva with 16S and piaB quantification.

RESULTS

The prevalence of pneumococcus-positive samples was highest at onset of ILI (18% or 42/232) and lowest among controls (13% or 26/194, and 11% or 22/194, at the first and second sampling moment, respectively), though these differences were not significant. Pneumococcal carriage was associated with exposure to young children (OR:2.71, 95%CI 1.51-5.02, p<0.001), and among asymptomatic controls with presence of rhinovirus infection (OR:4.23; 95%CI 1.16-14.22, p<0.05). When compared with carriers among controls, pneumococcal absolute abundances were significantly higher at onset of ILI (p<0.01), and remained elevated beyond recovery from ILI (p<0.05). Finally, pneumococcal abundances were highest in carriage events newly-detected after ILI-onset (estimated geometric mean 1.21E -5, 95%CI 2.48E -7-2.41E -5, compared with pre-existing carriage).

CONCLUSIONS

ILI exacerbates pneumococcal colonization of the airways in older adults, and this effect persists beyond recovery from ILI.

Disease burden of varicella versus other vaccine-preventable diseases before introduction of vaccination into the national immunisation programme in the Netherlands

Introduction

Estimating burden of disease (BoD) is an essential first step in the decision-making process on introducing new vaccines into national immunisation programmes (NIPs). For varicella, a common vaccine-preventable disease, BoD in the Netherlands was unknown.

Aim

To assess national varicella BoD and compare it to BoD of other vaccine-preventable diseases before their introduction in the NIP.

Methods

In this health estimates reporting study, BoD was expressed in disability-adjusted life years (DALYs) using methodology from the Burden of Communicable Diseases in Europe (BCoDE)-project. As no parameters/disease model for varicella (including herpes zoster) were available in the BCoDE toolkit, incidence, disease progression model and parameters were derived from seroprevalence, healthcare registries and published data. For most other diseases, BoD was estimated with existing BCoDE-parameters, adapted to the Netherlands if needed.

Results

In 2017, the estimated BoD of varicella in the Netherlands was 1,800 (95% uncertainty interval (UI): 1,800–1,900) DALYs. Herpes zoster mainly contributed to this BoD (1,600 DALYs; 91%), which was generally lower than the BoD of most current NIP diseases in the year before their introduction into the NIP. However, BoD for varicella was higher than for rotavirus gastroenteritis (1,100; 95%UI: 440–2,200 DALYs) and meningococcal B disease (620; 95%UI: 490–770 DALYs), two other potential NIP candidates.

Conclusions

When considering the introduction of a new vaccine in the NIP, BoD is usually estimated in isolation. The current approach assesses BoD in relation to other vaccine-preventable diseases’ BoD, which may help national advisory committees on immunisation and policymakers to set vaccination priorities.

Association of Influenza Activity and Environmental Conditions With the Risk of Invasive Pneumococcal Disease

IMPORTANCE

Streptococcus pneumoniae is the most commonly identified cause of bacterial pneumonia, and invasive pneumococcal disease (IPD) has a high case fatality rate. The wintertime coseasonality of influenza and IPD in temperate countries has suggested that pathogen-pathogen interaction or environmental conditions may contribute to IPD risk.

OBJECTIVES

To evaluate the short-term associations of influenza activity and environmental exposures with IPD risk in temperate countries and to examine the generalizability of such associations across multiple jurisdictions.

DESIGN, SETTING, AND PARTICIPANTS

This case-crossover analysis of 19 566 individuals with IPD from 1998 to 2011 combined individual-level outcomes of IPD and population-level exposures. Participants lived in 12 jurisdictions in Canada (the province of Alberta and cities of Toronto, Vancouver, and Halifax), Australia (Perth, Sydney, Adelaide, Brisbane, and Melbourne), and the United States (Baltimore, Providence, and Philadelphia). Data were analyzed in 2019.

EXPOSURES

Influenza activity, mean temperature, absolute humidity, and UV radiation at delays of 1 to 3 weeks before case occurrence in each jurisdiction.

MAIN OUTCOMES AND MEASURES

Matched odds ratios (ORs) for IPD associated with changes in exposure variables, estimated using multivariable conditional logistic regression models. Heterogeneity in effects across jurisdictions were evaluated using random-effects meta-analytic models.

RESULTS

This study included 19 566 patients: 9629 from Australia (mean [SD] age, 42.8 [30.8] years; 5280 [54.8%] men), 8522 from Canada (only case date reported), and 1415 from the United States (only case date reported). In adjusted models, increased influenza activity was associated with increases in IPD risk 2 weeks later (adjusted OR [aOR] per SD increase, 1.07; 95% CI, 1.01-1.13). Increased humidity was associated with decreased IPD risk 1 week later (aOR per 1 g/m3, 0.98; 95% CI, 0.96-1.00). Other associations were heterogeneous; metaregression suggested that combinations of environmental factors might represent unique local risk signatures. For example, the heterogeneity in effects of UV radiation and humidity at a 2-week lag was partially explained by variation in temperature (UV index: coefficient, 0.0261; 95% CI, 0.0078 to 0.0444; absolute humidity: coefficient, -0.0077; 95% CI, -0.0125 to -0.0030).

CONCLUSIONS AND RELEVANCE

In this study, influenza was associated with increased IPD risk in temperate countries. This association was not explained by coseasonality or case characteristics and appears generalizable. Absolute humidity was associated with decreased IPD risk in the same jurisdictions. The generalizable nature of these associations has important implications for influenza control and advances the understanding of the seasonality of this important disease.

Vaccination Coverage of the Elderly in Greece: A Cross-Sectional Nationwide Study

Vaccines are important for older adults, and the morbidity and mortality of vaccine-preventable diseases among older adults are high. There are limited data on vaccination coverage among elderly people in Greece. The aim of this observational study was to record the vaccination coverage for vaccines recommended by the National Vaccination Program in Greece for the elderly people ≥60 years old. Two hundred general practitioners (GPs) around the country from the primary healthcare system were invited to “participate,” and one hundred fifty from them participated in the present study. The GPs were selected using geographically stratified random sampling methodology. Two thousand and seventy-two participants participated in the present study: of which, 1043 were males and 1029 were females. The mean age of the participants was 73.3 years, and 83% vaccination coverage for flu vaccine, 49.5% for conjugate pneumococcal vaccine, and 23.5% for polysaccharide pneumococcal vaccine were recorded. In addition, the vaccination coverage for herpes zoster vaccine was 20%, while very low percentages were recorded for diphtheria, tetanus, pertussis, and polio vaccine for adults. We found significant gaps in vaccination coverage, especially with regard to pneumococcal, herpes zoster, and tetanus. On the contrary, influenza vaccination coverage was satisfactory.

The burden of pertussis in older adults: what is the role of vaccination? A systematic literature review

INTRODUCTION

Pertussis (whooping cough) is a vaccine-preventable disease; however, neither natural- nor vaccine-induced protection is life-long. Although generally not severe in adults, pertussis can be associated with complications in patients with chronic conditions such as asthma or chronic obstructive pulmonary disease, and can be readily transmitted to more vulnerable populations, including neonates before they complete their primary vaccination. Furthermore, as the global population ages, the health and economic burden of the disease is expected to rise. Areas covered: A systematic literature review was conducted to ascertain the current epidemiological and financial burden of pertussis in older adults and to discuss the potential value of a booster vaccination in this population. Expert commentary: Our review indicates a considerable underestimation of the pertussis burden amongst older adults. Seroprevalence studies consistently demonstrate that the reported incidence may be much lower than the actual incidence. Tetanus toxoid-reduced diphtheria toxoid and acellular pertussis vaccines are immunogenic in older adults, induce high booster responses and are well-tolerated. There is therefore a good rationale for the advocacy of booster pertussis vaccination throughout life to prevent pertussis infection and its transmission, especially in adults aged ≥50 years.

Challenges in adult vaccination

Life-long primary prevention interventions beginning and continuing throughout an individual's lifetime are increasingly seen as key to meeting the global healthcare challenges that accompany demographic changes - a concept referred to as "Healthy aging". In this perspective, vaccination is seen as part of a triad, together with healthy diet and exercise. Current adult vaccine coverage is lower than target vaccination rates in most developed countries, and so vaccine preventable diseases continue to present a substantial burden on health and healthcare resources, especially in older individuals. In part, this is due to lack of knowledge and understanding of the benefits of vaccination, inconsistent recommendations by providers and uncertainties about cost benefits. However, lower vaccine effectiveness in older adults plays a part, and new vaccines with novel characteristics to improve effectiveness in older adults are required. A life-course immunization approach to ensure optimal vaccine uptake across adults of all ages can be expected to reduce morbidity and mortality in later life. To achieve this, greater emphasis on public and healthcare provider education is necessary, based on appropriate economic analyses that demonstrate the overall value of vaccination. This article introduces the technical, economic, political and demographic issues that make establishing effective adult vaccination programs such a difficult, but pressing issue, and outlines some of the steps that are now being taken to address them. Key messages Life-long preventive activities that start and continue throughout life are essential, especially as the world's population is "getting older". This "Healthy aging" approach includes not only healthy diet and physical exercise; vaccination is critical in reducing some infectious diseases and their complications. Many adults, especially older adults (who have lower immunity than younger people) develop infections such as influenza and shingles that could potentially be prevented through vaccination. This review provides a perspective on the challenges in delivering a life-course immunization program. While some vaccines are less effective in older people, newer vaccines have been developed which provide stronger and longer protection in older patients than standard existing vaccines. However, the benefits of vaccination can only be realized if the vaccines are recommended and used. For that purpose, greater education of patients and their healthcare providers is necessary. Better knowledge of vaccines and making sure that all adults are up to date with all their recommended vaccines is an essential part of "Healthy aging". This should prevent not only vaccine-preventable diseases but also reduce the risk of complications in later life.

Immunogenicity and safety of an inactivated quadrivalent influenza vaccine co-administered with a 23-valent pneumococcal polysaccharide vaccine versus separate administration, in adults ≥50years of age: Results from a phase III, randomized, non-inferiority trial

INTRODUCTION

We compared co-administration versus separate administration of an inactivated quadrivalent influenza vaccine (IIV4) with a 23-valent pneumococcal polysaccharide vaccine (PPV23) in adults at high risk of complications of influenza and pneumococcal infection.

METHODS

This phase III, placebo-controlled, observer-blind trial (NCT02218697) was conducted in France and Belgium during the 2014-2015 influenza season. Adults≥50years of age meeting their country's vaccination recommendations were randomized 1:1 to co-administration or separate administration. Immunogenicity was assessed by hemagglutination inhibition (HI) titers for IIV4 and 22F-inhibition ELISA for PPV23. Co-primary objectives were to demonstrate non-inferiority of co-administration versus separate administration in terms of geometric mean titer (GMT) ratio for each influenza strain in the IIV4 and geometric mean concentration (GMC) ratio for six pneumococcal serotypes (1, 3, 4, 7F, 14, 19A) in the PPV23 in the per-protocol cohort (N=334).

RESULTS

The study met its co-primary objectives, with the upper limit of the 95% confidence interval of the GMT and GMC ratios (separate administration over co-administration) being ≤2.0 for all four antigens of the IIV4 and the six pre-selected serotypes of the PPV23, respectively. Immunogenicity of the IIV4 and PPV23 was similar regardless of administration schedule. In a post hoc analysis pooling participants ≥60years of age from the co-administration and separate administration groups, IIV4 immunogenicity was similar in higher risk adults with comorbidities (diabetes; respiratory, heart, kidney, liver, or neurological diseases; morbid obesity) versus those without. Both vaccines had an acceptable safety and reactogenicity profile; pain was the most common symptom, occurring more often with co-administration than separate administration.

CONCLUSION

The IIV4 and PPV23 can be co-administered without reducing antibody responses reflecting protection against influenza or pneumococcal disease. Co-administration of PPV23 at the annual influenza vaccination visit may improve uptake. Comorbidities had no impact on IIV4 immunogenicity, supporting its value in older adults with chronic medical conditions. Clinical Trial Registry Number: NCT02218697.

[Immunizing is not only a children's matter! : Why vaccinations are also important for adults]

Vaccinations belong to the ten most effective public health achievements worldwide. While immunization programms for children are installed in Europe, vaccinations for adults are not established. However, adult vaccination is extremely meaningful: increasing age means a higher susceptibility to infectious diseases, health problems and multimorbidity will increase. The burden of vaccine-preventable diseases is still high in Europe. Due to immunosenescence (older) adults are less protected against pathogens, antibody titers after vaccinations are lower and immunity lasts shorter. There is striking lack of data of adult vaccination rates and an international consensus regarding adult vaccination recommendations or guidelines are not available in Europe. In only six countries a comprehensive document describing recommended vaccinations for adults is available, among them Austria. The awareness of the importance of adult vaccination over the whole lifetime is not present to the necessary extent in Europe and has to be promoted.

Severe underestimation of pertussis related hospitalizations and deaths in the Netherlands: A capture-recapture analysis

OJECTIVE

Despite vaccination, pertussis has remained endemic, sometimes leading to severe disease. We aimed to quantify the completeness of reporting (CoR) of pertussis hospitalizations and deaths in the Netherlands.

STUDY DESIGN

CoR was estimated using capture-recapture analyses. Hospitalizations (2007-2014) from the National Registration Hospital Care (hospital data) were matched to the notifiable Infectious Disease case registry (notifications) providing (month and) year of birth, gender and postal code. Deaths (1996-2014) from Statistics Netherlands (death registry) were matched to notifications using gender, age, year of death and notification date. Cases <2years (y) and ≥2y were analysed separately. Chao's estimator estimated the total population, which was used to calculate CoR.

RESULTS

Using strict matching criteria, we found 461 matches among 876 (hospital data) and 757 (notifications) hospitalizations <2y. The population estimate of hospitalized infants was 1446, resulting in CoR between 52% and 61%. For hospitalizations ≥2y (246; hospital data and 264; notifications) 43 matches were found, with a population estimate of 1512 and CoR between 16.5% and 22%. Among thirteen (death registry) and eight (notifications) deaths <2y, seven cases overlapped. The population estimate was 16. CoR of the two sources was 50-81%. With two (death registry) and eight (notifications) deaths ≥2y without overlap, the population estimate was 26 and CoR 8-31%.

CONCLUSION

Results showed substantial underestimation of pertussis hospitalizations and deaths. This has to be taken into account in evaluation of current and future immunization programs.

The intention of Dutch general practitioners to offer vaccination against pneumococcal disease, herpes zoster and pertussis to people aged 60 years and older

BACKGROUND

Increasing life expectancy results in a larger proportion of older people susceptible to vaccine preventable diseases (VPDs). In the Netherlands, influenza vaccination is routinely offered to people aged 60 years and older. Vaccination against pneumococcal disease, herpes zoster and pertussis is rarely used. These vaccines will be evaluated by the Dutch Health Council and might be routinely offered to older people in the near future. Possible expansion of the program depends partly on the willingness of general practitioners (GPs) to endorse additional vaccinations. In this study, we assessed predictors of GPs' attitude and intention to vaccinate people aged 60 years and older.

METHODS

GPs (N = 12.194) were invited to fill in an online questionnaire consisting of questions about social cognitive factors that can influence the willingness of GPs to vaccinate people aged 60 years and older, including underlying beliefs, practical considerations of adding more vaccines to the national program, demographics, and GPs' patient population characteristics. The questionnaire was filled in by 732 GPs.

RESULTS

GPs were positive both about vaccination as a preventive tool and the influenza vaccination program, but somewhat less positive about expanding the current program. Prediction analysis showed that the intention of GPs to offer additional vaccination was predicted by their attitude towards offering additional vaccination, towards vaccination as a preventive tool, towards offering vaccination during an outbreak and on GPs opinion regarding suitability to offer additional vaccination (R2 = 0.60). The attitude of GPs towards offering additional vaccination was predicted by the perceived severity of herpes zoster and pneumonia, as well as the perceived incidence of herpes zoster. Severity of diseases was ranked as important argument to recommend vaccination, followed by effectiveness and health benefits of vaccines.

CONCLUSION

Providing GPs with evidence-based information about the severity and prevalence of diseases, and effectiveness and health benefits of the vaccines, together with an active role of GPs in informing older people about vaccines, could modify the intention towards additional vaccination of people 60 years and older.

Recommended immunization schedules for adults: Clinical practice guidelines by the Escmid Vaccine Study Group (EVASG), European Geriatric Medicine Society (EUGMS) and the World Association for Infectious Diseases and Immunological Disorders (WAidid)

Rapid population aging has become a major challenge in the industrialized world and progressive aging is a key reason for making improvement in vaccination a cornerstone of public health strategy. An increase in age-related disorders and conditions is likely to be seen in the near future, and these are risk factors for the occurrence of a number of vaccine-preventable diseases. An improvement in infectious diseases prevention specifically aimed at adults and the elderly can therefore also decrease the burden of these chronic conditions by reducing morbidity, disability, hospital admissions, health costs, mortality rates and, perhaps most importantly, by improving the quality of life. Among adults, it is necessary to identify groups at increased risk of vaccine-preventable diseases and highlight the epidemiological impact and benefits of vaccinations using an evidence-based approach. This document provides clinical practice guidance on immunization for adults in order to provide recommendations for decision makers and healthcare workers in Europe. Although immunization is considered one of the most impactful and cost-effective public health measures that can be undertaken, vaccination coverage rates among adults are largely lower than the stated goal of ≥ 95% among adults, and stronger efforts are needed to increase coverage in this population. Active surveillance of adult vaccine-preventable diseases, determining the effectiveness of the vaccines approved for marketing in the last 5 y, the efficacy and safety of vaccines in immunocompromised patients, as well as in pregnant women, represent the priorities for future research.