Gardasil, the HPV vaccine recommended for male and female adolescents and young adults, does not trigger autoimmune conditions such as lupus, type 1 diabetes or multiple sclerosis after vaccination in young women, according to a new study in the Journal of Internal Medicine, conducted by Kaiser Permanente.

Kaiser Permanente researchers used electronic health records to conduct an observational safety study of 189,629 females aged nine to 26 in California, who were followed for six months after receiving each dose of the quadrivalent HPV (human papillomavirus) vaccine from 2006 to 2008. Researchers found no increase in 16 pre-specified autoimmune conditions in the vaccinated population compared to a matched group of unvaccinated girls and women.

The quadrivalent HPV vaccine was licensed by the FDA in 2006 and recommended for young women and girls to protect against genital warts, which infect 6.2 million people annually, is the most common sexually transmitted infection in the U.S. and can lead to cervical cancer in women.

Autoimmune reactions have been a long-standing concern surrounding the vaccination and many parents withhold the vaccine from their children because of perceived safety concerns. However, most speculated associations have stemmed from case reports that have not been confirmed by large, controlled epidemiologic studies. This study presents findings from a well-designed, post-licensure safety study of the vaccine on a large, ethnically diverse population, researchers said.

"These findings offer some assurance that among a large and generalizable female population, no safety signal for autoimmune conditions was found following HPV4 vaccination in routine clinical use,” said study lead author Chun Chao, Ph.D., a research scientist at the Kaiser Permanente department of research and evaluation in Pasadena, Calif.

The study, funded by Merck, employed methods that involved in-depth medical chart review to ensure the accuracy of diagnosis and that onset of disease was after vaccination. In addition, disease incidence in the vaccinated group was compared with a comparable unvaccinated group. As a result, this study offers important complementary safety information for the HPV vaccine.