Factors associated with interest in bacterial sexually transmitted infection vaccines at two large sexually transmitted infection clinics in British Columbia, Canada

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.

Ensuring equity with pre-clinical planning for chlamydia vaccines

Chlamydia trachomatis (Ct) remains the most common bacterial sexually transmitted pathogen worldwide, causing significant morbidity particularly among women, including pelvic inflammatory disease, ectopic pregnancy, and infertility. Several vaccines are advancing through pre-clinical and clinical development, and it is likely that one or more vaccines will progress into human efficacy trials soon. In this Perspective, we present a case for considering the challenges of Ct vaccine development through a lens of equity and justice. These challenges include the need to protect against multiple serovars, in both females and males, at multiple anatomic sites, and in resource poor areas of the world. We propose that early consideration of vaccine implementation by conducting community-engaged research will ensure that a scientifically sound chlamydia vaccine promotes equity, justice, and shared-gendered responsibility for STI prevention.

Maternal perceptions of vaccinating boys against human papillomavirus (HPV) in Seoul, South Korea: A descriptive exploratory qualitative study

Human Papillomavirus (HPV) vaccination is of paramount importance to reduce HPV-associated cancers in both genders. In South Korea, the prophylactic vaccine is recognized as prevention of cervical cancer with little attention given to male HPV vaccination. The purpose of this study was to explore perceptions of male HPV vaccination and underlying factors for vaccine hesitancy among mothers of unvaccinated boys in Seoul, Korea using a qualitative method. We used a purposive sampling strategy to recruit mothers of unvaccinated middle school-aged boys living in one of the 25 districts in Seoul, supplemented by a snowball sampling approach. We conducted one-on-one telephone interviews with ten mothers using a semi-structured interview guide. Questions probed mothers' views on vaccinating boys against HPV and the reasons for not vaccinating their sons. We found that mothers were hesitant to vaccinate their sons against HPV due to high out-of-pocket costs, fear of side effects concerning the young age of their sons, and low awareness of HPV and HPV vaccine, all of which stemmed from the exclusion of male HPV vaccination in the national immunization program. Sociocultural factors, including vaccination norms, lack of HPV education, and values associated with sexually transmitted infections were also likely to negatively impact mothers' vaccination decision-making. Despite the barriers, mothers were willing to accept HPV vaccination when it was framed as cancer prevention for not only the sons but also their future spouses. In conclusion, reasons for Korean mothers' hesitancy for their sons' HPV vaccine uptake were multifaceted. Healthcare providers' role in emphasizing and conveying the importance of gender-neutral HPV vaccination will be essential to alleviate negative sentiments around the vaccine for boys and reduce their risk of compromised sexual health. As an effective public health strategy, tailored cancer prevention messages should be delivered heightening significant benefits of the HPV vaccine beyond the prevention of cervical cancer.

Factors associated with intention to receive vaccines for bacterial sexually transmitted infections among young HPV-vaccinated Canadian women

Objective

The aim of this study was to explore the acceptability of bacterial STI vaccines among young HPV-vaccinated Canadian women to inform future vaccine program implementation.

Methods

A 20-item cross-sectional questionnaire was administered from June 2019 to June 2020 to HPV-vaccinated participants of the pan-Canadian QUEST cohort. Multivariable logistic regression models assessed interest in chlamydia, syphilis, and gonorrhea vaccines using a priori variables and factors significant in bivariate analysis.

Results

Of the 1092 respondents analyzed, 82% indicated interest in receiving one or more future STI vaccines. Respondents had a median age of 19.6 years (range 16.9–23.4), and 75% of respondents identified as white/European descent. In adjusted analyses, intent to engage in positive health behaviours was associated with vaccine interest for syphilis (OR = 5.76, 95% CI 4.03–8.27), chlamydia (OR = 5.27, 95% CI 3.66–7.63), and gonorrhea (OR = 5.96, 95% CI 4.15–8.60). Willingness to pay for an STI vaccine was also associated with vaccine interest for syphilis (OR = 2.02, 95% CI 1.29–3.19), chlamydia (OR = 2.41, 95% CI 1.50–3.90), and gonorrhea (OR = 2.29, 95% CI 1.44–3.63). Ever having sexual intercourse and identifying as LGBTQ were significantly associated with vaccine interest for all infections, while age and ever being immunosuppressed were not significant in any adjusted models.

Conclusion

Findings indicate over 80% of participants in a cohort of young HPV-vaccinated Canadian women are interested in receiving future bacterial STI vaccines. Further exploration of STI vaccine acceptability among diverse populations is required to inform future bacterial STI vaccine program implementation.

Supplementary Information

The online version contains supplementary material available at 10.17269/s41997-022-00648-2.

Acceptability of a Gonococcal Vaccine Among Sexually Active Men Who Have Sex With Men

BACKGROUND

Prospects for a gonococcal vaccine have advanced. Vaccine acceptability is crucial to maximizing population-level protection among key groups, such as men who have sex with men (MSM). We assessed the prevalence of gonococcal vaccine acceptability among sexually active MSM in the United States.

METHODS

We used data from the American Men's Internet Study conducted from August 2019 to December 2019. We calculated frequencies of sociodemographic characteristics, vaccine acceptability, and preferred location for vaccine receipt. Using log-binomial regression analyses, we calculated unadjusted prevalence rates (PRs) and 95% confidence intervals (CIs) to evaluate factors associated with vaccine acceptability.

RESULTS

Of 4951 MSM, 83.5% were willing to accept a vaccine and 16.5% were unwilling. Preferred vaccination locations were primary care provider's clinics (83.5%) and sexually transmitted disease (STD) clinics (64.6%). Vaccine acceptability was greater among young MSM (15-24 years [PR, 1.09; 95% CI, 1.05-1.12], 25-29 years [PR, 1.13; 95% CI, 1.09-1.17], and 30-39 years [PR, 1.10; 95% CI, 1.05-1.14] compared with MSM ≥40 years), MSM living with HIV (PR, 1.05; 95% CI, 1.02-1.09), and MSM who reported (in the past 12 months) condomless anal sex (PR, 1.09; 95% CI, 1.06-1.12), a bacterial STD test (PR, 1.18; 95% CI, 1.15-1.21), HIV preexposure prophylaxis use (PR, 1.17; 95% CI, 1.14-1.19), a bacterial STD diagnosis (PR, 1.04; 95% CI, 1.02-1.07), or a health care provider visit (PR, 1.11; 95% CI, 1.06-1.16). Men who have sex with men who reported ≤high school education (PR, 0.93; 95% CI, 0.91-0.97) were less willing to accept a vaccine compared with those with >high school education.

CONCLUSIONS

Most respondents were willing to accept a gonococcal vaccine. These findings can inform the planning and implementation of a future gonococcal vaccination program that focuses on MSM.

Chlamydia trachomatis vaccines for genital infections: where are we and how far is there to go?

INTRODUCTION

Chlamydia trachomatis is the most common sexually transmitted bacterial pathogen in the world. Antibiotic treatment does not prevent against reinfection and a vaccine is not yet available.

AREAS COVERED

We focus the review on the progress made of our understanding of the immunological responses required for a vaccine to elicit protection, and on the antigens, adjuvants, routes of immunization and delivery systems that have been tested in animal models. PubMed and Google Scholar were used to search publication on these topics for the last 5 years and recent Reviews were examined.

EXPERT OPINION

The first Phase 1 clinical trial of a C. trachomatis vaccine to protect against genital infections was successfully completed. We expect that, in the next five years, additional vaccine clinical trials will be implemented.