Single dose of HPV vaccine may be enough

Credit BMJ

CANCER DIGEST – Dec. 28, 2019 – One dose of the HPV vaccine may be enough to prevent infection from the potential cancer-causing virus, according to new research published in JAMA Network.

The study led by Ashish Deshmukh, PhD, MPH, and Kalyani Sonawane, PhD from The University of Texas Health Science Center at Houston (UTHealth) showed that a single dose of the HPV vaccine may be as effective as the currently recommended two- or three-dose series.

Human papillomavirus (HPV) is a sexually transmitted virus thought to account for more than 90 percent of all cervical and anal cancers, more than 60 percent of all penile cancers, and approximately 70 percent of all oral cancers. The Centers for Disease Control (CDC) estimates that 34,800 cancers diagnosed each year are linked to HPV.

The study analyzed data from the National Health and Nutritional Examination Survey (NHANES) between 2009 and 2016. The ongoing survey began in 1956 collects sexual behavior, drug use, and nutritional data. The current data collection began in early 1999 and remains a continuous annual survey, collecting specimen and survey information from 7,000 randomly selected US residents each year. 

The researchers looked data from 1,620 women ages 18 to 26 in the study and HPV infections and stratified them by the number of vaccine doses received. Most of them, 1004, were unvaccinated, 106 had received 1 dose, 126 received 2 doses, and 384 received 3 doses.

Results showed that 12.5 percent of the unvaccinated had infection of one or more of four HPV strains linked to cancer compared to 2.4 percent of the women who had received one dose, 5.1 percent of those who had two doses and 3.1 percent of those with three doses.

From a statistical standpoint there was no significant difference in infection rates for those who had one, two or three doses of the vaccine.

The CDC recommends a two-dose regimen for all children starting the series before age 15 or a three-dose regimen if the series is started between ages 16 to 26.

The latest generation of HPV vaccine can protect against nearly 90 percent of cancer-causing HPV infections. Yet, current vaccinations rates are less than ideal – half of people in the U.S. are not vaccinated against this common sexually transmitted infection.

Sources: UT Health News and JAMA Network