Population effectiveness, not efficacy, should decide who gets vaccinated against human papillomavirus via publicly funded programs

Human Papillomavirus awareness and vaccine acceptability among men who have sex with men from mainland China

Reductions in persistent HPV infection and related diseases occurrence have been proved among vaccinated males. However, little was known on awareness of HPV and the vaccine in males, especially in high-risk subgroups such as men who have sex with men (MSM), in China. A multicenter cross-sectional study was conducted in MSM from 10 selected cities in mainland China. HPV awareness and vaccination acceptability were investigated through interviews and questionnaires. In total, 3057 eligible participants aged 18 years older from 10 cities were investigated. Only 20.6% (629/3057) of them had ever heard of HPV and 4.8% (146/3057) had heard of HPV vaccine. Factors that potentially influence willingness for HPV vaccination were found to be safety of the vaccine (54.2%, 1656/3057) and severity of HPV infection (52.3%, 1599/3057). After education, 97.8% (2882/2946) of participants would like to pay for HPV vaccination, and only a minority of them (2.5%, 75/2946) would like to afford more than 2000 RMB. Our results showed that the awareness on HPV and the vaccine were quite poor among MSM in mainland China. To promote the application of HPV vaccination in male populations, appropriate information delivery and education on HPV infection and health should be enhanced as well as in females.

Declines in Anogenital Warts Among Age Groups Most Likely to Be Impacted by Human Papillomavirus Vaccination, United States, 2006-2014

OBJECTIVES

To detect decreases in anogenital warts (AGW) among sex and age groups likely to be affected by human papillomavirus vaccination.

METHODS

We estimated annual AGW prevalence during 2006 to 2014 using health care claims among US private health insurance enrollees aged 15 to 39 years. We derived AGW diagnoses using 1 of the following: (1) condylomata acuminata diagnosis, (2) viral wart diagnosis combined with a benign anogenital neoplasm diagnosis or destruction or excision of an anogenital lesion, or (3) AGW medication combined with a benign anogenital neoplasm diagnosis or destruction or excision of an anogenital lesion.

RESULTS

Prevalence decreased during 2008 to 2014 among females aged 15 to 19 years (annual percentage change [APC] = -14.1%; P < .001) and during 2009 to 2014 among women aged 20 to 24 years (APC = -12.9%; P < .001) and among women aged 25 to 29 years (APC = -6.0%; P = .001). We observed significant declines among men aged 20 to 24 years (APC = -6.5%; P = .005). Prevalence increased or was stable in all other sex and age groups.

CONCLUSIONS

We observed AGW decreases among females in the age groups most likely to be affected by human papillomavirus vaccination and decreases in men aged 20 to 24 years. Decreased prevalence in young men is likely attributable to herd protection from vaccination among females.

How to best measure the effectiveness of male human papillomavirus vaccine programmes?

In many countries now, vaccination of young adolescent girls with prophylactic human papillomavirus (HPV) vaccines has been rolled out as a public health programme. In countries where coverage has been high, this has led to dramatic reductions in cervical high-grade precancerous lesions, as well as genital warts. A reduction in circulating vaccine-related HPV types has also been demonstrated. With the introduction of gender-neutral approaches incorporating universal vaccination of pre-adolescent boys in some countries, implementation of post-vaccine monitoring will be critical to evaluate the incremental impact of male vaccination. In contrast to cervical screening programmes, population-wide screening for HPV infection or related disease in males is not recommended; hence real-time monitoring of HPV vaccine effectiveness in males will require dedicated surveillance strategies. Monitoring the prevalence of circulating genital HPV types using a sentinel surveillance model could offer a good surrogate marker of early vaccine effectiveness in males. However, such an approach requires careful consideration of the most appropriate anatomical sites from which to collect specimens, the best sampling methods and the most sensitive assays to use. Additionally, in assessing an accurate measure of the impact of HPV vaccination in the male population, the effect of herd protection will need to be assessed, as most male programmes will commence in the setting of established female programmes. This poses an interesting epidemiological challenge.

HPV vaccine acceptability among men: a systematic review and meta-analysis

OBJECTIVE

To understand rates of human papillomavirus (HPV) vaccine acceptability and factors correlated with HPV vaccine acceptability.

DESIGN

Meta-analyses of cross-sectional studies.

DATA SOURCES

We used a comprehensive search strategy across multiple electronic databases with no date or language restrictions to locate studies that examined rates and/or correlates of HPV vaccine acceptability. Search keywords included vaccine, acceptability and all terms for HPV.

REVIEW METHODS

We calculated mean HPV vaccine acceptability across studies. We conducted meta-analysis using a random effects model on studies reporting correlates of HPV vaccine acceptability. All studies were assessed for risk of bias.

RESULTS

Of 301 identified studies, 29 were included. Across 22 studies (n=8360), weighted mean HPV vaccine acceptability=50.4 (SD 21.5) (100-point scale). Among 16 studies (n=5048) included in meta-analyses, perceived HPV vaccine benefits, anticipatory regret, partner thinks one should get vaccine and healthcare provider recommendation had medium effect sizes, and the following factors had small effect sizes on HPV vaccine acceptability: perceived HPV vaccine effectiveness, need for multiple shots, fear of needles, fear of side effects, supportive/accepting social environment, perceived risk/susceptibility to HPV, perceived HPV severity, number of lifetime sexual partners, having a current sex partner, non-receipt of hepatitis B vaccine, smoking cigarettes, history of sexually transmitted infection, HPV awareness, HPV knowledge, cost, logistical barriers, being employed and non-white ethnicity.

CONCLUSIONS

Public health campaigns that promote positive HPV vaccine attitudes and awareness about HPV risk in men, and interventions to promote healthcare provider recommendation of HPV vaccination for boys and mitigate obstacles due to cost and logistical barriers may support HPV vaccine acceptability for men. Future investigations employing rigorous designs, including intervention studies, are needed to support effective HPV vaccine promotion among men.

Prevalence of anogenital warts among participants in private health plans in the United States, 2003-2010: potential impact of human papillomavirus vaccination

OBJECTIVES

We estimated anogenital wart prevalence from 2003 to 2010 by gender and age group in a large US cohort with private insurance to detect potential decreases among people most likely to be affected by human papillomavirus (HPV) vaccination.

METHODS

We restricted health care claims to those from individuals aged 10 to 39 years with continuous insurance within a given year. We derived anogenital wart diagnoses from a diagnosis of condyloma acuminata, or either a less specific viral wart diagnosis or genital wart medication combined with either a benign anogenital neoplasm or destruction or excision of a noncervical anogenital lesion.

RESULTS

Prevalence increased slightly in 2003 to 2006, then significantly declined in 2007 to 2010 among girls aged 15 to 19 years; increased in 2003 to 2007, remained level through 2009, and declined in 2010 among women aged 20 to 24 years; and increased through 2009 but not in 2010 for women aged 25 to 39 years. For males aged 15 to 39 years, prevalence for each 5-year age group increased in 2003 to 2009, but no increases were observed for 2010.

CONCLUSIONS

These data indicate reductions in anogenital warts among US females aged 15 to 24 years, the age group most likely to be affected by introduction of the HPV vaccine.

Quadrivalent human papillomavirus vaccine effectiveness: a Swedish national cohort study

Background

Incidence of condyloma, or genital warts (GW), is the earliest possible disease outcome to measure when assessing the effectiveness of human papillomavirus (HPV) vaccination strategies. Efficacy trials that follow prespecified inclusion and exclusion criteria may not be fully generalizable to real-life HPV vaccination programs, which target a broader segment of the population. We assessed GW incidence after on-demand vaccination with quadrivalent HPV vaccine using individual-level data from the entire Swedish population.

Methods

An open cohort of girls and women aged 10 to 44 years living in Sweden between 2006 and 2010 (N > 2.2 million) was linked to multiple population registers to identify incident GW in relation to HPV vaccination. For vaccine effectiveness, incidence rate ratios of GW were estimated using time-to-event analyses with adjustment for attained age and parental education level, stratifying on age at first vaccination.

Results

A total of 124 000 girls and women were vaccinated between 2006 and 2010. Girls and women with at least one university-educated parent were 15 times more likely to be vaccinated before age 20 years than girls and women whose parents did not complete high school (relative risk ratio = 15.45, 95% confidence interval [CI] = 14.65 to 16.30). Among those aged older than 20 years, GW rates declined among the unvaccinated, suggesting that HPV vaccines were preferentially used by women at high risk of GW. Vaccination effectiveness was 76% (95% CI = 73% to 79%) among those who received three doses of the vaccine with their first dose before age 20 years. Vaccine effectiveness was highest in girls vaccinated before age 14 years (effectiveness = 93%, 95% CI = 73% to 98%).

Conclusions

Young age at first vaccination is imperative for maximizing quadrivalent HPV vaccine effectiveness.

Modeling preventative strategies against human papillomavirus-related disease in developed countries

Over the last 5 years, prophylactic vaccination against human papillomavirus (HPV) in pre-adolescent females has been introduced in most developed countries, supported by modeled evaluations that have almost universally found vaccination of pre-adolescent females to be cost-effective. Studies to date suggest that vaccination of pre-adolescent males may also be cost-effective at a cost per vaccinated individual of ~US$400-500 if vaccination coverage in females cannot be increased above ~50%; but if it is possible, increasing coverage in females appears to be a better return on investment. Comparative evaluation of the quadrivalent (HPV16,18,6,11) and bivalent (HPV16,18) vaccines centers around the potential trade-off between protection against anogenital warts and vaccine-specific levels of cross-protection against infections not targeted by the vaccines. Future evaluations will also need to consider the cost-effectiveness of a next generation nonavalent vaccine designed to protect against ~90% of cervical cancers. The timing of the effect of vaccination on cervical screening programs will be country-specific and will depend on vaccination catch-up age range and coverage and the age at which screening starts. Initial evaluations suggest that if screening remains unchanged, it will be less cost-effective in vaccinated compared to unvaccinated women but, in the context of current vaccines, will remain an important prevention method. Comprehensive evaluation of new approaches to screening will need to consider the population-level effects of vaccination over time. New screening strategies of particular interest include delaying the start age of screening, increasing the screening interval and switching to primary HPV screening. Future evaluations of screening will also need to focus on the effects of disparities in screening and vaccination uptake, the potential effects of vaccination on screening participation, and the effects of imperfect compliance with screening recommendations. This article forms part of a special supplement entitled "Comprehensive Control of HPV Infections and Related Diseases" Vaccine Volume 30, Supplement 5, 2012.