Inmunización en Manada...y HPV

Study Suggests Herd Protection for Some HPV Strains

By Kelly Young

Edited by David G. Fairchild, MD, MPH, and Jaye Elizabeth Hefner, MD

A decade after the introduction of the human papilloma virus (HPV) vaccine, a Pediatrics study suggests there is some evidence of herd immunity among young women in the U.S.

Researchers compared the HPV vaccination history of nearly 1600 13- to 26-year-old sexually experienced females in Cincinnati. From 2006 to 2017, the proportion who received at least one dose of the HPV vaccine increased from 0% to 84%.

During that time, the percentage of vaccinated females who were infected with one of the strains in the 4-valent vaccine, licensed in 2006, fell 81%. Infections with one of the other five strains in the 9-valent vaccine, licensed in 2014, fell 69% in this group. Those who were unvaccinated also saw a 40% reduction in 4-valent vaccine-type HPV infections.

However, unvaccinated females saw a nonsignificant increase in infections of the five other strains in the 9-valent vaccine. The authors say it could be because these patients may have been more likely to engage in risky behaviors.

Pediatrics article (Free abstract)

Pediatrics online-first page (if above link doesn't work) (Free)

Background: NEJM Journal Watch Women's Health coverage of study suggesting lack of herd immunity (Your NEJM Journal Watch registration required)