Contrary to concerns that getting vaccinated against human papilloma virus (HPV) will lead young people to have more or riskier sex, a new study in England finds less risky behaviour among young women who got the HPV vaccine, reports Reuters Health. "To my knowledge no studies have shown that HPV vaccination increases risky sexual behaviour among young women and some of these studies have shown this (less risky behaviour) is also the case outside of the UK," said Dr Laura Sadler of the University of Manchester, who led the study.
It's possible that getting vaccinated led to better education about sexual health, Sadler and her colleagues write. Sadler and other experts say it’s also possible that young women who are already less likely to take risks are the ones who are more likely to get vaccinated. Even though public health officials recommend that girls and young women be vaccinated against HPV, some parents have hesitated, fearing that it could encourage sexual activity or unsafe sex.
For their study, Sadler's team reviewed the medical records of 363 women born in 1990 or later who attended an English clinic. Almost two-thirds of the young women in the group had received at least one dose of the vaccine. Full vaccination requires three vaccine shots.
The researchers compared the womens' histories of behaviours that are risky in themselves or tend to be linked to risky sexual behaviour, such as not using condoms, having sex for the first time when they were 15 or younger, having six or more sexual partners and drinking alcohol two or more times a week. They found five variables related to sexual behaviour that were significantly different between women who had been vaccinated and those who hadn't. Women who were not vaccinated were more likely to have had three sex partners in the last six months, to have attended the clinic with symptoms of a sexually transmitted disease, to have had anal intercourse with their last sexual contact and to have tested positive for Chlamydia (a common sexually transmitted infection) at their clinic visit.
Being vaccinated, in contrast, was associated with less-risky behaviours, such as using condoms. "The women in our study were mainly from the catch-up vaccine programme – older teens – and as in the other studies, it shows that among this group, vaccination was taken up by those demonstrating other types of preventive or less risky behaviours," Sadler said.
In a study in the US, Anupam B Jena, of Harvard Medical School, Boston, and co-authors used a large insurance database of females (ages 12 to 18) from 2005 through 2010 to examine STIs among girls who were vaccinated and those who were not.
The authors found use of the vaccination increased over time with 27.3% of females receiving the vaccination by the end of 2010 compared with just 2.5% of females at the end of 2006. The study included 21,610 females who were vaccinated against HPV and 186,501 matched females who were non-vaccinated.
The study found that females who were vaccinated were more likely to be sexually active in the year before vaccination compared with those who were non-vaccinated. Study results also indicate that vaccinated females had higher rates of STIs before and after vaccination compared with those who were nonvaccinated. For example, the rates of STIs in the year before vaccination were higher among HPV-vaccinated females (94 of 21,610, 4.3 per 1,000) compared with nonvaccinated females (522 of 186,501, 2.8 per 1,000). The rates of STIs increased both for vaccinated (147 of 21,610, 6.8 per 1,000) and nonvaccinated (781 of 186,501, 4.2 per 1,000) girls in the year after vaccination. The difference in odds between the two groups implies that the HPV vaccination was not associated with an increase in STIs relative to the growth of STIs among nonvaccinated females.
"We found no evidence that HPV vaccination leads to higher rates of STIs. Given low rates of HPV vaccination among adolescent females in the US our findings should be reassuring to physicians, parents and policy makers that HPV vaccination is unlikely to promote unsafe sexual activity," the study concludes.
[link url="http://www.reuters.com/article/2015/02/12/us-womens-health-hpv-behavior-idUSKBN0LG2GE20150212"]Full Reuters Health report[/link]
[link url="http://jfprhc.bmj.com/content/early/2015/01/20/jfprhc-2014-100896.abstract"]Journal of Family Planning and Reproductive Health Care abstract[/link]
[link url="http://media.jamanetwork.com/news-item/hpv-vaccination-not-associated-with-increase-in-sexually-transmitted-infections/"]JAMA press release[/link]
[link url="http://archinte.jamanetwork.com/solr/searchresults.aspx?q=Anupam%20B%20Jena&fd_JournalID=71&f_JournalDisplayName=JAMA%20Internal%20Medicine&SearchSourceType=3"]JAMA Internal Medicine abstract[/link]