by Dr. C.H. Weaver M.D. 7/2019
The HPV (human papilloma virus) vaccine appears to be more effective than expected according to a study published in Lancet. Vaccination not only reduces rates of HPV infection and the presence of precancerous cells in the cervix in people who receive the vaccine, it also reduces the incidence of HPV related diseases in individuals who were not vaccinated.
HPV is the leading cause of cervical cancer. The virus can also cause other cancers, including cancers of the penis, head and neck, as well as conditions like genital warts. The HPV vaccine was introduced in 2006 and more than 115 countries and territories have implemented it in their vaccination programs.
The analysis published in Lancet evaluated published studies that measured changes in the number of new HPV infections, genital warts or pre-cancerous changes in the cervix in countries before and after they adopted routine HPV vaccination in girls. Overall a total of 65 studies including more than 60 million people living in 14 countries were represented in the analyses.
The researchers found that, in these countries...
- There was a significant decrease in the prevalence of HPV 16, and 18 that cause 70 percent of cervical cancers.
- There was a decrease in the prevalence of precancerous cells in the cervix as measured by a PAP smear.
- In countries where at least half the target population was vaccinated there was a decrease in the prevalence of HPV-related diseases even among those who weren’t vaccinated.
- There was a decrease in genital warts diagnoses among unvaccinated boys and older women
The decrease in HPV related diseases is evidence of herd immunity and occurs because there are fewer individual with HPV overall.
The Centers for Disease Control currently recommends that all genders receive vaccination; everyone should receive the first of two vaccine doses by age 12. The World Health Organization (WHO) does recommend that girls 9 to 13 get vaccinated against HPV, it does not yet recommend that all genders receive the vaccination. The WHO recommendation is likely to expand to all genders given the increasing evidence of “herd immunity” reducing the incidence of HPV related diseases.