HPV Vaccination Significantly Reduced HPV Rates in Women

The prevalence of vaccine-targeted human papillomavirus (HPV) types has decreased sharply in the Kingdom of Bhutan, offering the first evidence of the effectiveness of a high-coverage national vaccination program in a lower-middle-income country.

Scientists from the International Agency for Research on Cancer (IARC) and partner institutions conducted a study to estimate the effectiveness of a vaccination program against HPV that was implemented in Bhutan in 2010 for women aged 12–18 years.

These researchers announced on September 22, 2020, this vaccination program achieved almost 90 percent coverage of the target population. And, the prevalence of vaccine-targeted HPV types decreased sharply.

The researchers used data from 2 cross-sectional surveys, conducted in 2011–2012 and in 2018, which enabled them to examine responses in more than 3,000 participants.

Between the 2 surveys, the prevalence of HPV vaccine types decreased from 8.3% to 1.4%, whereas the prevalence of non-vaccine types increased from 25.8% to 31.4%. 

The overall and indirect adjusted VE against vaccine-targeted HPV types was 88% (95% CI, 80% to 92%) and 78% (CI, 61% to 88%), respectively. 

Among women younger than 27 years, who were targeted by the vaccination program, the overall and indirect adjusted VE was 93% (CI, 87% to 97%) and 88% (CI, 69% to 95%), respectively. 

No impact on nonvaccine HPV types was detectable in this study.

The presence of HPV DNA was assessed in cervical cell samples from sexually active women aged 17–29 years to estimate age- and sexual behavior-adjusted overall, total, and indirect (herd immunity) HPV vaccine effectiveness.

In a video published on the Annals of Internal Medicine website, Dr. Iacopo Baussano, the study’s lead author, explains the main findings and the impact of the study.

The primary funding source for this study was the Bill & Melinda Gates Foundation.

An updated list of authorized and experimental HPV vaccines is found on this webpage. 

Vax-Before-Cancer publishes research-based cancer prevention news.