Study Finds No Link Between HPV Vaccine and Increased STIs

Gardasil Vaccine BottleDespite fears from certain groups, the HPV vaccine does not promote risky sexual disinhibition. A new study published in the journal JAMA Internal Medicine concludes that that HPV vaccination was not associated with increases in sexually transmitted infections (STIs).

Human papillomavirus (HPV) is a virus that affects the skin and the moist membranes of the body such as the cervix, anus, mouth, and throat. Although most HPV infections clear without any harmful effects, the virus also causes genital warts and cancers of the cervix, vagina, vulva, anus, penis, and throat. HPV affects one-quarter of women between the ages of 14 and 19 in the United States and 45 percent of women between the ages of 20 and 24.

Despite the prevalence of the virus, vaccination with the HPV vaccine remains low. Only 38 percent of women complete all three recommended doses, and only 57 percent receive a single dose.

For the present study, researchers led by Anupam B. Jena, M.D., Ph.D., of the Harvard Medical School in Boston sought to study whether HPV vaccination of females is associated with increases in STI rates.

Using a large, longitudinal insurance database of females in the United States between the ages of 12 and 18 years old insured between January 1, 2005 and December 31, 2010, the researchers followed a total of 208,111 women. Of the total women, 21,610 were vaccinated against HPV. The vaccinated women were then age-matched with women who did not receive the HPV vaccine.

According to the study, vaccinated women were more likely to be sexually active in the year prior to receiving the HPV vaccine compared to women in the control group. Vaccinated women also had higher rates of STIs, both before and after vaccination, than the non-vaccinated women.


Rates of STIs also increased in both groups after vaccination. However, the rates increased comparably among vaccinated and non-vaccinated women, indicating that vaccination against HPV was not associated with a relative increase in the rate of STIs.

In other words, the HPV vaccine is unlikely to promote unsafe sexual activity.

Writes Robert A. Bednarczyk, Ph.D., of Emory University in Atlanta in a related commentary, “These findings should not come as a surprise to researchers in the field of HPV vaccinology and should serve as continued reassurance that HPV vaccination does not lead to sexual disinhibition,” adding, “Addressing this knowledge gap through the development and delivery of information relative to all key partners (adolescents, their parents and their health care professionals) will be critical in removing the stigma of HPV vaccine in our efforts to fully use this vaccine.”


Two vaccines that protect against HPV exist: Cervarix and Gardasil. Gardasil is a quadrivalent vaccine, protecting against four types of HPV. Cervaris is a bivalent vaccine, protecting against two types of HPV. The Centers for Disease Control and Prevention (CDC) in the United States currently recommends that the HPV vaccine be given as a series of three shots over six months starting at age 9 for both girls and boys. The Food and Drug Administration (FDA) approved Gardasil 9 (Human Papillomavirus 9-valent Vaccine, Recombinant), which provides protection against five more strains of HPV than the previous Gardasil, in December.

Another recent study found that the HPV vaccine does not increase the risk of multiple sclerosis or any other similar central nervous system conditions.


HPV Vaccination Not Associated with Increase in Sexually Transmitted Infections:
Human Papillomavirus Vaccine and Sexual Activity: How Do We Best Address Parent and Physician Concerns?:
Incidence of Sexually Transmitted Infections After Human Papillomavirus Vaccination Among Adolescent Females:
Study Finds No Link Between HPV Vaccination and Increase in STIs:

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Written by Heather

Heather is a writer, librarian, linguist, wife, homemaker, homeschooler, and mother.

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