Understanding predictors of pneumococcal vaccine uptake in older adults aged 65 years and older in high-income countries across the globe: A scoping review

Influenza and pneumococcal vaccine hesitancy in the elderly population: results from two representative surveys in Germany

BACKGROUND

The reasons for low influenza and pneumococcal vaccine acceptance in the elderly population are largely unknown - despite the great need of vaccines in this risk group. While many studies examine the relationship between factors influencing vaccination, such as sociodemographic characteristics and influenza and pneumococcal vaccination intentions and behavior, psychological factors, such as vaccine-specific attitudes, are underutilized in research on vaccination behaviors and intervention strategies. This article assesses the psychological antecedents of influenza and pneumococcal vaccination in the elderly and assesses the predictive power of psychological vs. sociodemographic and other factors surrounding vaccination, on vaccination behavior.

METHODS

A cross-sectional telephone survey, representative of age, gender and rural/urban residence, was conducted with N = 701 German participants > 60 years of age, during the influenza season of 2016-17. Multiple logistic regressions were conducted to identify the relevant determinants of vaccination behavior.

RESULTS

Results show unique patterns in the psychological antecedents: while confidence, the belief in the effectiveness of vaccination and calculation, the need for information, complacency, the lack of risk perception and constraints, and perceived practical barriers to vaccination predicted influenza vaccination behavior, only complacency predicted pneumococcal vaccination behavior. The amount of explained variance in influenza vaccination behavior nearly doubles when psychological antecedents of vaccination are taken into account, beyond other factors surrounding vaccination. However, the effect was smaller for pneumococcal vaccination behavior. The results are compared to a subnational sample.

CONCLUSIONS

Understanding the psychological drivers of vaccination can help to plan interventions effectively.

TRIAL REGISTRATION

Deutsches Register Klinische Studien (German Clinical Trials Register) DRKS00012653. Registered 24.11.2017. Retrospectively registered.

Maintaining Immunizations for Vaccine-Preventable Diseases in a Changing World

Immunization has saved an estimated 154 million lives over the past 50 years since the launch of the Essential (formerly Expanded) Program on Immunization in 1974, representing 6 lives saved every minute, every year, for 50 years. But achieving and maintaining high immunization coverage have required sustained political and public commitment, financial resources, strong partnerships, research and innovation, and communication and advocacy. New and evolving challenges to maintaining high immunization coverage have emerged alongside long-standing stubborn obstacles. We review some of these key challenges to immunization in this dynamic, changing world and summarize some promising solutions. Success in some regions of the world in eliminating polio, measles, and rubella, and reducing morbidity and mortality from other vaccine-preventable diseases, should provide hope that progress can be made in achieving and maintaining high immunization coverage. We cannot afford to do otherwise.

How well does vaccine literacy predict intention to vaccinate and vaccination status? A systematic review and meta-analysis

This review quantified the association of vaccine literacy (VL) and vaccination intention and status. PubMed, Scopus, and Web of Science were searched. Any study, published until December 2022, that investigated the associations of interest were eligible. For each outcome, articles were grouped according to the vaccine administrated and results were narratively synthesized. Inverse-variance random-effect models were used to compare standardized mean values in VL domain(s) between the two groups: individuals willing vs. unwilling to get vaccinated, and individuals vaccinated vs. unvaccinated. This review of 18 studies shows that VL strongly predicts the vaccination intention while its association with vaccination status is attenuated and barely significant, suggesting that other factors influence the actual vaccination uptake. However, given the scarce evidence available, the heterogeneity in the methods applied and some limitations of the studies included, further research should be conducted to confirm the role of VL in the vaccination decision-making process.

Determinants of pneumococcal vaccination among older adults: A scoping review

OBJECTIVES

To identify the range of factors that impact health behaviours pertaining to the uptake of pneumococcal vaccination (PV) among older persons.

STUDY DESIGN

Scoping review.

METHODS

This review followed Arksey and O'Malley's framework. Five databases: PubMed, CINAHL, PsycINFO, Scopus and Embase were searched for relevant studies on PV uptake among outpatient older adults ≥65 years published between January 2013 and October 2023. Data were extracted and verified using a standardised template, and synthesised using inductive content analysis. Findings were classified according to Andersen's behavioural model of health services use (BMHSU).

RESULTS

Twenty-seven papers were included in the final analysis. Reception of PV was influenced by predisposing factors such as (i) awareness and risk perception, (ii) demographic characteristics, and (iii) cultural beliefs towards preventive medicine; enabling factors including (i) disease and vaccine literacy, (ii) past experience with preventive health services, and (iii) access to relevant resources; as well as reinforcing factors namely, (i) vaccine efficacy and safety, (ii) social influence, (iii) support from healthcare professionals, and (iv) vaccine administration environment.

CONCLUSIONS

Older adults' health behaviours, particularly their attitudes towards vaccination are often complex and this attests to the need for multidimensional, cross-sector barrier-specific strategies to raise PV coverage. Key issues identified in this review highlight the focus areas that healthcare providers, policy makers and other stakeholders should collaborate on to resolve underutilisation of preventive medicine and promote health among this population.

Changes in the Pneumococcal Vaccination Uptake and Its Determinants before, during, and after the COVID-19 Pandemic among Community-Living Older Adults in Hong Kong, China: Repeated Random Telephone Surveys

Pneumococcal vaccination (PV) is effective in preventing vaccine-type pneumococcal diseases. This study investigated the changes in PV uptake and its determinants before, during, and after the Coronavirus Disease 2019 (COVID-19) pandemic among community-living older adults aged ≥65 years in Hong Kong, China. Three rounds of random telephone surveys were conducted every two years from May 2019 to October 2023. Multivariate logistic regression models were fitted to examine the between-round differences in PV uptake rate and factors associated with PV uptake in each round. This study included 1563 participants. The standardized PV uptake rate in Round 1, 2, and 3 was 17.3%, 28.3%, and 35.5%, respectively. A significant difference in the PV uptake rate was found between Rounds 2 and 1 (p = 0.02), but not between Rounds 3 and 2 (p = 0.98). Perceived barriers, cue to action and self-efficacy, were significant determinants of PV uptake in all rounds. Perceived benefits were significant determinants of PV uptake in the first and second rounds, but not in the third round. Continuous monitoring of PV uptake and its determinants, and evaluating and adjusting the PV program, might contribute to the success of such a vaccination program in the post-pandemic era.

Commentary on: Cost-effectiveness of pneumococcal vaccination and of programs to increase its uptake in U.S. older adults

See related articles by Wateska et al.

Exploring missed opportunities for influenza vaccination and influenza vaccine co-administration patterns among Italian older adults: a retrospective cohort study

BACKGROUND

Missed opportunities constitute a main driver of suboptimal seasonal influenza vaccination (SIV) coverage in older adults. Vaccine co-administration is a way to reduce these missed opportunities. In this study, we quantified missed opportunities for SIV, identified some of their socio-structural correlates and documented SIV co-administration patterns.

METHODS

In this registry-based retrospective cohort study, we verified the SIV status of all subjects aged ≥65 years who received at least one dose of coronavirus disease 2019 (COVID-19), pneumococcal or herpes zoster vaccines during the 2022/23 influenza season. The frequency of concomitant same-day administration of SIV with other target vaccines was also assessed.

RESULTS

Among 41 112, 5482 and 3432 older adults who received ≥1 dose of COVID-19, pneumococcal and herpes zoster vaccines, missed opportunities for SIV accounted for 23.3%, 5.0% and 13.2%, respectively. Younger, male and foreign-born individuals were generally more prone to missing SIV. The co-administration of SIV with other recommended vaccines was relatively low, being 11.0%, 53.1% and 17.1% in COVID-19, pneumococcal and herpes zoster cohorts, respectively.

CONCLUSIONS

A sizeable proportion of older adults who received other recommended vaccines during the last influenza season did not receive SIV. This share of missed opportunities, which are subject to some social inequalities, may be addressed by increasing vaccine co-administration rates and implementing tailored health promotion interventions.

The Association of Health Literacy with Intention to Vaccinate and Vaccination Status: A Systematic Review

Despite health literacy (HL) being recognized as a driver of health-promoting behavior, its influence on the vaccination decision-making process remains unclear. This study summarized current evidence on the association between HL and both intention to vaccinate and vaccination status. We searched PubMed, Scopus, and Web of Science, retrieving observational studies published until January 2022 that used HL-validated tools to investigate the above associations for any vaccine. Quality was assessed using the Newcastle-Ottawa scale. Twenty-one articles were included; of these, six investigated the intention to vaccinate and the remainder vaccination status. Articles on intention looked at SARS-CoV-2 vaccination using heterogeneous HL tools and were of high/fair quality. Vaccination status, mainly for influenza or pneumococcal vaccines, was explored using various HL tools; the quality was generally high. We found inconsistent results across and within vaccine types, with no clear conclusion for either vaccination intention or status. A weak but positive association was reported between a high HL level and influenza vaccination uptake for individuals aged more than 65 years. HL did not seem to significantly influence behavior towards vaccination. Differences in the methods used might explain these results. Further research is needed to investigate the role of HL in the vaccination decision-making process.

Pneumococcal vaccination uptake and missed opportunities for vaccination among Canadian adults: A cross-sectional analysis of the Canadian Longitudinal Study on Aging (CLSA)

Introduction

In Canada, pneumococcal vaccination is recommended to all adults aged ≥65 and those <65 who have one or more chronic medical conditions (CMCs). Understanding vaccine uptake and its determinants among eligible groups has important implications for reducing the burden of pneumococcal disease.

Methods

Using data from a large national cohort of Canadian residents aged ≥47 years between 2015–2018, we calculated self-reported pneumococcal vaccine uptake among eligible groups, estimated associations between key factors and non-vaccination, assessed missed opportunities for vaccination (MOV) and examined risk factors for MOV. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for relevant associations were estimated through logistic regression.

Results

45.8% (95% CI: 45.2–46.5) of 22,246 participants aged ≥65 and 81.3% (95% CI: 80.5–82.0) of 10,815 individuals aged 47–64 with ≥1 CMC reported never having received a pneumococcal vaccine. Receipt of influenza vaccination in the previous year was associated with the lowest odds of pneumococcal non-vaccination (aOR = 0.14 [95% CI: 0.13–0.15] for older adults and aOR = 0.23 [95% CI: 0.20–0.26] for those aged 47–64 with ≥1 CMC). Pneumococcal vaccine uptake was also more likely in case of contact with a family doctor in the previous year (versus no contact), increased with age and varied widely across provinces. Among individuals recently vaccinated against influenza, 32.6% (95% CI: 31.9–33.4) of those aged ≥65 and 71.1% (95% CI: 69.9–72.3) of those aged 47–64 with ≥1 CMC missed an opportunity to get a pneumococcal vaccine. Among individuals who had contact with a family doctor, 44.8% (95% CI: 44.1–45.5) of those aged ≥65 and 80.4% (95% CI: 79.6–81.2) of those aged 47–64 with ≥1 CMC experienced a MOV.

Conclusions

Pneumococcal vaccine uptake remains suboptimal among at-risk Canadian adults who are eligible for vaccination. Further research is needed to clarify the reasons behind missed opportunities for vaccination and adequately address the main barriers to pneumococcal vaccination.