Gender-neutral vaccination is superior for eradication of oncogenic strains of human papillomavirus (HPV), suggest the results of a community-randomised modelled trial published in the Journal of Infectious Diseases.
Researchers randomised 33 Finnish communities into gender-neutral HPV16/18 vaccination, girls-only HPV16/18 vaccination, and hepatitis B-virus vaccination arms.
In 2007-2010, 11,662/20,513 of 40,852/39,420 resident boys/girls from 1992-1995 birth cohorts consented. In 2010-14, cervicovaginal samples from vaccinated and unvaccinated girls at age 18.5 years were typed for HPV6/11/16/18/31/33/35/39/45/51/52/56/58/59/66/68. Vaccine efficacy (VE) for vaccinated girls, herd effect (HE) for unvaccinated girls, and the protective effectiveness (PE) for all girls, were estimated. The researchers extended the community-randomised trial results about vaccination strategy with mathematical modelling to assess HPV eradication.
The HE and PE estimates in the 1995 birth cohort for HPV18/31/33 were significant in the gender-neutral arm, and 150% and 40% stronger than in the girls-only arm. Concordantly, HPV18/31/33 eradication was predicted in adolescents/young adults in already 20 years with 75% coverage of gender-neutral vaccination. With the 75% coverage, eventual HPV16 eradication was also predicted, but only with the gender-neutral strategy.
“The results have definitely influenced the decision about offering HPV vaccination to boys [in Sweden in 2020], which more and more countries are also deciding,” said Matti Lehtinen, who led the study.