New opportunity for vaccinating older people: well-child clinic visits

Adult vaccination uptake strategies in low- and middle-income countries: A systematic review

BACKGROUND

Evidence-based strategies can maximize vaccination intent and uptake among adults. This systematic review summarizes the existing literature on strategies to improve vaccination intent and uptake among adults in low- and middle-income countries (LMICs) to inform future implementation in various populations and contexts.

METHODS

Eligible studies were identified through a systematic search in Medline, Embase, Cochrane Libraries, as well as grey literature databases published between January 2010 and March 2021. The search was limited to studies in LMICs that evaluated adult vaccination interventions. Data were extracted from the included studies and evaluated against the World Health Organization's Behavioral and Social Drivers of Vaccination Framework. The National Institutes of Health study quality assessment tools were used to evaluate study quality.

RESULTS

The initial literature review identified 2,854 records, 22 of which met the inclusion criteria. The majority (n = 19 or 86%) of studies were from middle-income countries, with the remaining studies (n = 3 or 13%) set in low-income countries. The majority (15/22, 68%) of interventions were multi-component. 82% (18/22) of studies addressed thoughts and feelings, 59% (13/22) addressed social processes, and 73% (16/22) addressed practical issues. Five studies reported primary outcomes of vaccination intent, and the remaining 17 reported vaccine uptake. 36% (8/22) of the studies cited statistically significant positive intervention effects on vaccination intent or uptake. Few of the included studies (6/22, 27%) were RTCs, and most studies (15/22, 68%) were of poor study quality. The studies reporting the highest increase in vaccination intent and uptake were multi-component interventions that addressed all three determinants of vaccination.

DISCUSSION

The results of this review highlight levers that can be used to encourage vaccine intent and uptake in the ongoing rollout of COVID-19 vaccines, as well as the deployment of other vaccines to adult populations in LMICs. Of the included studies, multicomponent interventions were most effective, mainly when targeting multiple determinants of vaccination. However, poor study quality indicates the need for additional research to validate these findings.

Factors associated with pneumococcal polysaccharide vaccination of the elderly in Spain: A cross-sectional study

Vaccination of the elderly is an important factor in limiting the impact of pneumonia in the community. The aim of this study was to investigate the factors associated with pneumococcal polysaccharide vaccination in patients aged ≥ 65 years hospitalized for causes unrelated to pneumonia, acute respiratory disease, or influenza-like illness in Spain. We made a cross-sectional study during 2013-2014. A bivariate analysis was performed comparing vaccinated and unvaccinated patients, taking into account sociodemographic variables and risk medical conditions. A multivariate analysis was performed using multilevel regression models. 921 patients were included; 403 (43.8%) had received the pneumococcal vaccine (394 received the polysaccharide vaccine). Visiting the general practitioner ≥ 3 times during the last year (OR = 1.79; 95% CI 1.25-2.57); having received the influenza vaccination in the 2013-14 season (OR = 2.57; 95% CI 1.72-3.84) or in any of the 3 previous seasons (OR = 11.70; 95% CI 7.42-18.45) were associated with receiving the pneumococcal polysaccharide vaccine. Pneumococcal vaccination coverage of hospitalized elderly people is low. The elderly need to be targeted about pneumococcal vaccination and activities that encourage healthcare workers to proactively propose vaccination might be useful. Educational campaigns aimed at the elderly could also help to increase vaccination coverages and reduce the burden of pneumococcal disease in the community.

Comorbid risk, respondent characteristics and likelihood of pneumococcal vaccination versus no vaccination among older adults in Brazil

This study investigated predictors of pneumococcal polysaccharide vaccine (PPV) use among older adults in Brazil. Respondents aged ≥50 from 2011 National Health and Wellness Survey in Brazil who had ever (vs never) received PPV were compared on comorbid risk, sociodemographics and vaccination behaviors. Logistic regression and decision tree analyses predicted PPV receipt as a function of the measures. Among 3195 respondents, 8.7% reported ever receiving PPV (10.4% among those at risk). Adjusting for covariates, adults classified as high or moderate risk had significantly greater odds of pneumococcal vaccination (odds ratios [ORs]: 2.42 or 1.36, respectively), as were those who received flu vaccinations (OR: 2.21) or were parents/guardians of a vaccinated child (OR: 6.48). In Brazil, child vaccination appears to be the dominant predictor of adult PPV uptake, followed by influenza vaccination. Higher disease risk was a significant predictor, but most older at-risk adults (89.6%) did not receive PPV.