Getting the shots: methods to gain adherence to a multi-dose vaccination program for inner city, drug-involved prostitution communities

Behavioral interventions for vaccination uptake: A systematic review and meta-analysis

BACKGROUND

Human behavior and more specifically behavioral insight-based approaches to vaccine uptake have often been overlooked. While there have been a few narrative reviews indexed in Medline on behavioral interventions to increase vaccine uptake, to our knowledge, none have been systematic reviews and meta-analyses covering not just high but also low-and-middle income countries.

METHODS

We included 613 studies from the Medline database in our systematic review and meta-analysis categorizing different behavioral interventions in 9 domains: education campaigns, on-site vaccination, incentives, free vaccination, institutional recommendation, provider recommendation, reminder and recall, message framing, and vaccine champion. Additionally, considering that there is variability in the acceptance of vaccines among different populations, we assessed studies from both high-income countries (HICs) and low- to middle-income countries (LMICs), separately.

FINDINGS

Our results showed that behavioral interventions can considerably improve vaccine uptake in most settings. All domains that we examined improved vaccine uptake with the highest effect size associated with provider recommendation (OR: 3.4 (95%CI: 2.5-4.6); Domain: motivation) and on-site vaccination (OR: 2.9 (95%CI: 2.3-3.7); Domain: practical issues). While the number of studies conducted in LMICs was smaller, the quality of studies was similar with those conducted in HICs. Nevertheless, there were variations in the observed effect sizes.

INTERPRETATION

Our findings indicate that "provider recommendation" and "on-site vaccination" along with other behavioral interventions can be employed to increase vaccination rates globally.

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.

Low prevalence, low immunization and low adherence to full hepatitis B vaccine scheme and high-risk behaviors among crack cocaine users in central Brazil

Crack cocaine users represent a target group for hepatitis B vaccination. We evaluate the HBV epidemiology, immunization status and compliance with a super-accelerated vaccination schedule among in-treatment crack cocaine users in central Brazil. Six hundred in-treatment crack cocaine users were interviewed, and serum samples were tested for HBV markers. A super-accelerated vaccination schedule of HBV vaccine was offered to all susceptible crack cocaine users. In total, 7.0% of those tested had at least one positive marker of HBV exposure. Age, use of crack cocaine through improvised pipe, exchange of sex for money/drugs and previous sexually transmitted infections (STIs) were predictors of HBV exposure. One hundred six (17.7%) individuals showed a serological profile of hepatitis B vaccination. Of these, 54.7% were less than 25 years old, and only 13% of individuals were more than 35 years old. Although 91.8% of crack users accepted the first vaccine dose, only 21.7% received all three doses. Of the 23 crack cocaine users who agreed to have their vaccine response evaluated, 78.3% developed protective anti-HBs titers. Premature termination of treatment was the most common reason for not receiving the full vaccine series. Despite the low prevalence of HBV exposure among in-treatment crack cocaine users in central Brazil, the low rate of immunization and the high frequency of high-risk behaviors highlight the potential for crack users to acquire and disseminate this infection and therefore maintain the viral reservoir. Health practitioners need to keep this in mind, taking advantage of all opportunities to access this population and vaccinate against HBV.