New research supports the recent U.S. recommendation for two, rather than three, doses of the human papillomavirus (HPV) vaccine to protect against genital warts in preteens and teens.

Investigators at Boston University Medical Center found that two HPV vaccine doses are just as effective as three at preventing genital warts. That’s in keeping with the new recommendations from the U.S. Center for Disease Control and Prevention.

The CDC and World Health Organization based the new two-dose schedule primarily on “immunogenicity” results — the vaccine’s ability to induce an immune response, said study lead author Dr. Rebecca Perkins. “But there was very little research on how effective that recommendation has been,” added Perkins, an obstetrician.

“This study validates the new recommendations, and allows us to confidently move forward with the two-dose schedule for the prevention of genital warts,” she said in a medical center news release.

The HPV vaccine is currently recommended for all boys and girls between the ages of 9 and 14. HPV is a sexually transmitted virus that can also lead to cervical, vaginal and anal cancers.

Researchers say that since 2007, as more parents have chosen to vaccinate their kids, the incidence of genital warts has dropped significantly.

The new study assessed the prevalence of warts among nearly 400,000 girls. The researchers looked to see whether they’d been vaccinated against HPV, and if so, how many doses they had had.

Beyond the conclusion that two doses were just as protective as three, the study found that both dose regimens offered much more protection against genital warts than a single dose or no vaccine at all.

However, the findings do not speak to additional HPV-related health concerns, such as cervical dysplasia (a precancerous condition) or cancer.

The study was published online in the June issue of the journal Sexually Transmitted Diseases.

More information

There’s more on HPV at the U.S. Centers for Disease Control and Prevention.

Source: HealthDay