HPV vaccination in Hong Kong: Misconceptions, myths and money

A survey of 851 parents in Hong Kong finds that awareness and acceptance of human papillomavirus (HPV) vaccination for children are lower among parents of boys vs girls, and that main reasons for vaccine hesitancy are concerns about vaccine side effects and the belief that their child is too young to be vaccinated against HPV.

Persistent infections with high-risk, oncogenic types of HPV are associated with cancers of the cervix, vulva, vagina, penis, and oropharynx. [WHO IARC Monographs on The Evaluation of Carcinogenic Risks to Humans, 2007: Human Papillomaviruses; Cancer Epidemiol Biomarkers Prev 2015;24:1548-1556] “HPV vaccination is a safe and highly effective method for preventing cervical and other HPV-related cancers,” wrote the researchers. [Tumour Virus Res 2022;13:200234; Lancet Infect Dis 2015;15:565-580; J Infect Dis 2019;219:382-390] “The present study investigated the awareness, perceptions, and acceptance of HPV vaccination for children among parents in Hong Kong.”

Parents of children in Primary 5–6 (age, 10–12 years) were invited to participate in an online survey consisting of 26 questions, which explored factors associated with, and differences in, vaccine acceptance and hesitancy between parents of girls and boys. [Hong Kong Med J 2023;doi:10.12809/hkmj2210470]

The survey was conducted in early February 2021, when only girls were eligible for HPV vaccination through Hong Kong’s no-cost school-based Childhood Immunisation Programme (CIP), which remained the case as of August 2023.  [https://www.fhs.gov.hk/english/main_ser/child_health/child_health_recommend.html] Therefore, parents of girls answered questions about HPV vaccine acceptance/hesitancy and awareness of HPV vaccination being included within the CIP. Parents of boys answered similar questions about HPV vaccine acceptance/hesitancy, HPV vaccine availability and appropriateness for boys, and whether inclusion in the CIP would influence their decision making.

Lower acceptance among parents of boys

Overall, 88.1 percent of parents of girls accepted HPV vaccination. Of their daughters, 14.2 percent had already been vaccinated and 85.8 percent were expected to undergo vaccination soon. At the same time, only 68.5 percent of parents of boys were aware that boys were eligible for HPV vaccination and among them, only 39.5 percent had consented to HPV vaccination. “The acceptance rates revealed in the present study … are considerably lower than the overall acceptance rate of 98 percent for CIP vaccines in Hong Kong,” remarked the researchers.

“The current market price for two doses of the HPV vaccine in Hong Kong is approximately HKD 3,000–5,000, which could be a prohibitive cost for some families [with cost being] identified as a key factor in many studies. Our findings indicate that if the government provided no-cost HPV vaccination for boys, an additional 30 percent of parents of boys would agree to vaccination. Incorporation of the HPV vaccine into the CIP may [also] enhance parental confidence,” they added. [BMC Public Health 2015;15:935; Vaccine 2006;24:7238-7245]

Parents whose children were enrolled in the CIP were more likely to consent to HPV vaccination vs parents whose children were not enrolled in the CIP (79.7 percent vs 33.7 percent; odds ratio [OR], 7.70, 95 percent confidence interval [CI], 5.39–11.01; p<0.001). Further subgroup analysis of parents whose children were enrolled in the CIP showed higher likelihood of accepting HPV vaccination among those who were aware vs unaware of the government’s no-cost HPV vaccination programme (63.4 percent vs 10.2 percent; OR, 15.3; 95 percent CI, 6.41–36.61; p<0.001).

Gender-neutral HPV vaccination programme recommended

The associations of HPV infection with anal, penile, and oropharyngeal cancers, as well as genital warts, have prompted 57 countries (including Germany, the UK, and Australia) to introduce gender-neutral vaccination into their national immunization schedules to provide greater and more equitable prevention of HPV-related diseases in their respective populations. [Bundesgesundheitsbl 2018;61:1170-1186; BMJ 2018;362:k3237]

“We recommend the adoption of a gender-neutral HPV vaccination programme in Hong Kong,” wrote the researchers. “A gender-neutral vaccination programme can achieve the goal of HPV eradication with a lower coverage rate of 55–70 percent rather than the 80–90 percent coverage required when only girls are vaccinated. In many advanced countries [eg, US, Germany, and France], HPV vaccination coverage rates remain low [20–40 percent]. Therefore, girls-only vaccination programmes are unlikely to eliminate HPV-related diseases.” [Expert Rev Vaccines 2019;18:153-160]

Myths and barriers: Vaccine safety and children’s age

In the survey, most parents indicated that the main reason for their children to undergo HPV vaccination was prevention of cancers (68.8 percent and 68.7 percent for parents of girls and boys, respectively), followed by prevention of sexually transmitted diseases (67.3 percent and 68.3 percent for parents of girls and boys, respectively). They also agreed that the optimal vaccination timing was before initiation of sexual activity (62.8 percent and 59.8 percent for parents of girls and boys, respectively).

Parental misconceptions regarding vaccine safety and ideal vaccination age were identified as major barriers to HPV vaccination for children. The most common reason for vaccine hesitancy was the belief that serious side effects could occur (66.7 percent and 68.0 percent for parents of girls and boys, respectively), followed by the belief that their children were too young (60.0 percent and 54.0 percent for parents of girls and boys, respectively), and the belief that the vaccine would interfere with growth (55.0 percent and 48.0 percent for parents of girls and boys, respectively).

“The notion of poor HPV vaccine safety is one of the main myths that must be dispelled by communicating its safety profile, which has been validated by decades of clinical trials and postlicensure studies involving tens of thousands of participants,” wrote the researchers. [Hum Vaccin Immunother 2019;15:1628-1638]

The view of their children as being too young to be vaccinated against HPV was consistent with 40.5 percent of respondents expecting their child to begin dating at the age of 15–17 years and a further 36.8 percent not expecting their child to date until ≥18 years of age. However, in an earlier survey of adolescents concerning sexual health and their first sexual encounter, >10 percent of respondents reported having had sex at or before the age of 15–16 years. [Hong Kong AIDS Foundation, A survey on “First Sex and Sexual Health”, 2018] Furthermore, according to another study on youth sexuality in Hong Kong, approximately 30 percent of 12- to 14-year-olds and 60 percent of 14- to 18-year-olds reported dating. [The Family Planning Association of Hong Kong, Report on Youth Sexuality Study, 2017]

“In addition to considering the potential for earlier-than-expected initiation of sexual activity, parents should [be made aware] that there is a biological reason to vaccinate earlier. Data from clinical trials show that HPV antibody titres are both higher and more persistent among individuals who undergo vaccination at a younger age,” advised the researchers. [Hum Vaccin Immunother 2019;15:1628-1638; JAMA 2013;309:1793-1802; MMWR Recomm Rep 2014;63:1-30; Hum Vaccin Immunother 2016;12:20-29]