In the Journals: HPV Vaccine and Herd Immunity

Researchers from the National Cancer Institute and Ohio State University investigated evidence for herd immunity against oral and pharyngeal HPV infections in U.S. men and women ages 18 to 59 years of age from 2009 to 2016 (Chaturvedi, AK, et al. Prevalence of oral HPV infection in unvaccinated men and women in the United States, 2009-2016. JAMA. 2019 Sep 10;322(10):977-979).

During 2009-2016, HPV vaccination rates increased from 0% to 5.8% in men and from 7.3% to 15.1% in women. In unvaccinated men, vaccine-type oral HPV prevalence declined from 2.7% during 2009-2010 to 1.6% during 2015-2016. During those same periods, the prevalence of non-HPV vaccine serotypes remained unchanged. These data are supportive of the presence of herd immunity in men. In unvaccinated women ages 18 to 59 years, oral HPV vaccine prevalence for serotypes contained in the vaccine remained unchanged, suggesting a lack of herd immunity in women.

The authors concluded that herd immunity in unvaccinated men likely arises from increased levels of vaccine immunity in women in the U.S. population. On the other hand, the lack of herd immunity in unvaccinated women probably reflects a low level of statistical power owing to the low prevalence of oral HPV infections in women.