HPV Vaccine Does Not Increase Likelihood of Unsafe Sex for Girls, Study Says HPV vaccine is used to stop the virus that can cause cancer.

 -- The vaccine used to guard against the human papillomavirus does not lead young people and teens to engage in more unsafe sex, according to a study released today.

The HPV vaccine has been on the market since 2006, but is not as widely used as other recommended vaccines, according to the federal Centers of Disease Control and Prevention.

The vaccine, given in three doses, is recommended for both boys and girls between the ages of 11 and 12. Just one dose of the vaccine cut down the risk of contracting HPV by 82 percent, according to a 2010 CDC study.

In spite of its success, just 57 percent of female teens received at least one dose and 38 percent of male teens had received all three doses in 2013, according to the CDC.

Dr. Anupam Jena, lead author of the study and a physician at Massachusetts General Hospital, said one likely cause for the low use of vaccine is that many parents and physicians are apprehensive about the possibility that the vaccine could lead to an increase in unsafe sex among teens and young adults.

“I’d like to emphasize that it’s a real concern. It’s not something to automatically dismiss but that’s why we need some scientific evidence to show we’re on the right path,” said Jena, an assistant professor of Health Care Policy and Medicine at the Harvard Medical School.

In the study published in the Journal of the American Medical Association, Jena and his colleagues combed an insurance database to figure out whether people who had the vaccine had higher rates of sexually transmitted infections than those who did not get the vaccine.

The researchers looked at the medical history between 2005 and 2010 of 21,000 girls between the ages of 12 to 18, who had been given the vaccine, and compared them with 180,000 women who did not have the vaccine. The study found that the vaccinated women did not have higher rates of sexually transmitted infections, suggested they did not have increased rates of unsafe sex.

Jena said U.S. HPV vaccination rates pale in comparison to similar countries such as Australia, where around 80 to 90 percent of eligible young people are vaccinated. He said he hoped the research would encourage parents and physicians to get their children vaccinated.

"This is a reasonable concern to have had, but the evidence suggests that it’s not important," Jena said. "[Physicians] can be reassured by these findings and use them to talk to their patients."

Robert Bednarczyk, assistant professor in the Hubert Department of Global health at Rollins School of Public Health at Emory University in Atlanta, wrote a commentary on the study for the Journal of the American Medical Association and said physicians have not recommended the vaccine as much as other recommended vaccines given to teens such as shots for meningitis.

Because HPV is a sexually transmitted virus, Bednarczyk said some doctors are uncomfortable talking about potential sexual activity with their patients and their parents.

“Some of them even said, ‘I think 11 is too young to have this discussion with patient,” Bednarczyk said.

But Bednarczyk points out the vaccine is supposed to be given well before an adolescent is exposed to the virus through possible sexual activity and that the way the virus is transmitted does not need to be discussed in detail.

"Do you go into a detailed discussion about why it can spread and how it can spread?" said Bednarczyk, who pointed out doctors don't often go into great detail about how bacterial meningitis is spread before they suggest their patients get vaccinated. "This is a vaccine that’s recommended for you and it’s going to keep you from getting sick."

Bednarczyk also pointed out another reason the shot is recommended at a young age is because younger patients tend to have a stronger immune response than older teens.