Public willingness to receive chlamydia, gonorrhea, syphilis, and trichomoniasis vaccines: a scoping review.

BACKGROUND: Sexually transmitted infections (STIs) like chlamydia, gonorrhea, syphilis, and trichomoniasis contribute significantly to global morbidity and mortality. Researchers are pursuing vaccines for these STIs, and a clinical trial is currently underway for a chlamydia vaccine. However, there is little research available on individuals' willingness to receive chlamydia, gonorrhea, syphilis, and trichomoniasis vaccines. The purpose of this analysis was to map the existing literature we have on individuals' willingness to receive these bacterial/parasitic STI vaccines and understand what information on vaccine acceptability is still needed. METHODS: We searched seven databases for literature on STI vaccine acceptability, then conducted title/abstract and full-text reviews to assess eligibility. All reviews and abstractions were conducted blindly by two reviewers, with discrepancies settled by discussion or the input of a third reviewer. RESULTS: Eight of the original 2,259 texts of interest met inclusion criteria. After data abstraction, we found that gonorrhea was the most commonly examined, followed by chlamydia and syphilis. Trichomoniasis vaccine acceptability was not reported. Most texts reported high acceptability, but there did not appear to be data describing how vaccine characteristics affect acceptability. Similarly, while the literature covers a variety of populations, most of the study populations were based out of the United States or Canada and were patrons of healthcare facilities or participants from a larger health intervention study. Therefore, more information is needed on populations outside North America, and on groups with lower healthcare access and utilization. CONCLUSION: As the incidence of bacterial and parasitic STIs increase, and as we grow nearer vaccines for these illnesses, understanding how likely the public is to accept and receive these vaccines is crucial to their success. While the existing literature describes STI vaccine acceptability in a variety of populations, their overall number is small. More research into STI vaccine acceptability outside of North America, and especially examining how factors like number of doses, timing, and cost influence vaccine acceptability is needed to ensure effective future vaccine rollouts.

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.