Modeling HPV vaccination scale-up among urban young men who have sex with men in the context of HIV

Inclusion of marginalized populations in HPV vaccine modeling: A systematic review

OBJECTIVE

Models simulating the potential impacts of Human Papillomavirus (HPV) vaccine have been used globally to guide vaccination policies and programs. We sought to understand how and why marginalized populations have been incorporated into HPV vaccine simulation models.

METHODS

We conducted a systematic search of PubMed, CINAHL, Scopus, and Embase to identify studies using simulation models of HPV vaccination incorporating one or more marginalized population through stratification or subgroup analysis. We extracted data on study characteristics and described these overall and by included marginalized groups.

RESULTS

We identified 36 studies that met inclusion criteria, which modeled vaccination in 21 countries. Models included men who have sex with men (MSM; k = 16), stratification by HIV status (k = 9), race/ethnicity (k = 6), poverty (k = 5), rurality (k = 4), and female sex workers (k = 1). When evaluating for a marginalized group (k = 10), HPV vaccination was generally found to be cost-effective, including for MSM, individuals living with HIV, and rural populations. In studies evaluating equity in cancer prevention (k = 9), HPV vaccination generally advanced equity, but this was sensitive to differences in HPV vaccine uptake and use of absolute or relative measures of inequities. Only one study assessed the impact of an intervention promoting HPV vaccine uptake.

DISCUSSION

Incorporating marginalized populations into decision models can provide valuable insights to guide decision making and improve equity in cancer prevention. More research is needed to understand the equity impact of HPV vaccination on cancer outcomes among marginalized groups. Research should emphasize implementation - including identifying and evaluating specific interventions to increase HPV vaccine uptake.

Factors influencing HPV vaccination willingness among men who have sex with men in China: a structural equation modeling analysis

Men who have sex with men (MSM) are at high risk of infection with human papillomavirus (HPV). Some countries have incorporated MSM into their HPV vaccination strategies. The acceptance of the HPV vaccine is an important factor affecting vaccine promotion in MSM. This study aims to analyze the factors influencing HPV vaccination willingness among MSM in China. Non-probability sampling was used to recruit MSM in China in June 2021. The information collected included demographic characteristics, HPV knowledge, attitude, behavior, history of sexually transmitted diseases (STDs), and HPV vaccination intention. A structural equation model was used to analyze the data based on the theory of knowledge-attitude-behavior. Among 889 participants, 736 (82.79%) of the MSM were willing to receive the HPV vaccine. The results of the structural equation model showed that knowledge, attitude, behavior, and STD history influenced the vaccination intention, of which knowledge (total effect of .36) and attitude (total effect of .31) had the greatest influence. Since most MSM in China were willing to be vaccinated against HPV, they should be considered for inclusion in the HPV vaccination program. Enhancing HPV awareness and improving risk awareness may be useful in increasing the vaccination willingness of MSM in China.

Uptake of Human Papillomavirus Vaccination by HIV Status and HIV Pre-exposure Prophylaxis (PrEP) Care Engagement Among Young Sexual Minority Men 17-24 Years Old in the USA

Introduction

HIV and human papillomavirus (HPV) are common sexually transmitted infections among young sexual minority men (YSMM) that are prevented by pre-exposure prophylaxis (PrEP) and HPV vaccination, respectively. We sought to determine the association between a history of PrEP use and HPV vaccination uptake among YSMM.

Methods

Data were collected from an online survey of YSMM (n = 287; M age = 20.6 years, range: 17-24; 58% Black or Latinx) recruited from social media and men-for-men geosocial networking apps in 2020 and analyses were conducted using chi-squared comparisons and Poisson regression using STATA (IC) version 15.1.

Results

About half (45.0%) of YSMM reported receiving at least one dose of the HPV vaccine. Controlling for other factors, YSMM who were living with HIV or had used PrEP were significantly more likely to have received at least one dose of an HPV vaccine (PR = 2.48, 95% CI = 1.52-4.07; PR = 1.70, 95% CI = 1.26-2.31, respectively).

Conclusions

YSMM living with HIV or with PrEP use experience reported higher rates of HPV vaccination compared to their counterparts, potentially due to greater utilization of health care or contacts with providers attuned to their health needs. Nevertheless, HPV vaccination uptake is suboptimal given the high prevalence of high-risk HPV genotypes among YSMM.

Policy Implications

Standard of care for YSMM should include revisiting HPV vaccination status and discussion of PrEP and other HIV prevention methods given suboptimal rates of HPV and PrEP uptake among this priority population for HPV vaccination, anal cancer, and HIV prevention.

Burden of vaccine-preventable diseases among at-risk adult populations in the US

Life-course immunization holds significant benefit for population health by reducing the burden of vaccine-preventable diseases (VPD) through vaccinating individuals at different stages and circumstances in life. The study aimed to determine the epidemiologic, clinical, economic, and societal burden of VPDs among at-risk adult subpopulations in the United States. A systematic literature review was conducted for articles published between January 2010 and June 2020, which identified 72 publications. There was heterogeneity in available epidemiology data, with the prevalence of VPDs ranging from 1.1% to 68.7%. Where the disease burden was described, outcomes were typically worse among high-risk subpopulations than in the general population. Several VPDs, including herpes zoster, meningococcal, and pneumococcal infections were associated with increased costs. This review suggests that subpopulations may not frequently interact with the healthcare system, or their risk factors may not be recognized by healthcare providers, and therefore individuals may not be appropriately targeted for vaccination.

Vaccine uptake and barriers to vaccination among at-risk adult populations in the US

To reduce morbidity and mortality associated with vaccine-preventable diseases (VPD), it is imperative that vaccination programs are implemented and prioritized throughout all stages of life across all populations. This study aimed to determine vaccine uptake and barriers to vaccination against VPDs among at-risk adult populations in the United States. We conducted a systematic literature review for articles published between January 2010 and June 2020 and identified 153 publications. The review identified 17 at-risk populations. Vaccine uptake was suboptimal among many populations, with factors including age, gender, and disease severity, associated with uptake. This review identified several barriers that impact vaccine uptake among at-risk populations, with concerns over safety, vaccine costs, lack of insurance, and lack of provider recommendation commonly reported across populations. Embracing a national life-course immunization framework that integrates developing policies, guidelines, and education would be a step to addressing these barriers.

Countering the rise of syphilis: A role for doxycycline post-exposure prophylaxis?

Doxycycline post-exposure prophylaxis (PEP) holds the potential to mitigate increasing rates of syphilis among sexual minority men (SMM) in the US yet has received limited attention. Since evaluation of this intervention in actual populations is not currently feasible, we used agent-based models (ABM) to assess the population-level impact of this strategy. We adapted ABM of HIV and HPV transmission, representing a population of 10,230 SMM in Philadelphia, Pennsylvania, US. Parameter inputs were derived from the literature, and ABM outputs during the pre-intervention period were calibrated to local surveillance data. Intervention scenarios varied doxycycline uptake by 20, 40, 60, 80 and 100%, while assuming continued condom use and syphilis screening and treatment. Under each intervention scenario, we incorporated treatment adherence at the following levels: 0, 20, 40, 60, 80 and 100%. Long-term population impact of prophylactic doxycycline was measured using the cumulative incidence over the 10-year period and the percentage of infections prevented attributable to doxycycline at year 10. An uptake scenario of 20% with an adherence level of 80% would reduce the cumulative incidence of infections by 10% over the next decade, translating to 57 fewer cases per 1000 SMM. At year 10, under the same uptake and adherence level, 22% of infections would be prevented due to doxycycline PEP in the instances where condoms were not used or failed. Findings suggest that doxycycline PEP will have a modest impact on syphilis incidence when assuming a reasonable level of uptake and adherence. Doxycycline PEP may be most appropriate as a secondary prevention measure to condoms and enhanced syphilis screening for reducing infections among SMM.

HPV-associated anal lesions in HIV+ patients: long-term results regarding quality of life

PURPOSE

HIV infection and concomitant HPV-associated anal lesions may significantly impact on patients' quality of life (QoL), as they are predicted to have negative effects on health, psyche, and sexuality.

MATERIAL AND METHODS

Fifty-two HIV+ patients with HPV-associated anal lesions were enrolled in a survey approach after undergoing routine proctologic assessment and therapy for HPV-associated anal lesions if indicated over a time span of 11 years (11/2004-11/2015). Therapy consisted of surgical ablation and topic treatment. QoL was analyzed using the SF-36 and the CECA questionnaires.

RESULTS

Fifty-two of 67 patients (77.6%) were successfully contacted and 29/52 provided full information. The mean age was 43.8 ± 12.8 years. The median follow-up from treatment to answering of the questionnaire was 34 months. Twenty-one percent (6/29) of the patients reported suffering from recurrence of condyloma acuminata, three patients from anal dysplasia (10.3%). In the SF-36, HIV+ patients did not rate their QoL as significantly different over all items after successful treatment of HPV-associated anal lesions. In the CECA questionnaire, patients with persisting HPV-associated anal lesions reported significantly higher emotional stress levels and disturbance of everyday life compared to patients who had successful treatment (71.9/100 ± 18.7 vs. 40.00/100 ± 27.4, p = 0.004). Importantly, the sexuality of patients with anal lesions was significantly impaired (59.8/100 ± 30.8 vs. 27.5/100 ± 12.2, p = 0.032).

CONCLUSION

HPV-associated anal lesions impact significantly negative on QoL in HIV+ patients. Successful treatment of HPV-associated anal lesions in HIV+ patients improved QoL. Specific questionnaires, such as CECA, seem to be more adequate than the SF-36 in this setting.