TUESDAY, Jan. 6, 2015 (HealthDay News) -- The HPV vaccine for cervical cancer and other diseases doesn't increase the risk for multiple sclerosis or other central nervous system disorders, according to a new study.
More than 175 million doses of HPV vaccines have been distributed worldwide to girls and young women -- and more recently males -- since 2006. Unconfirmed reports in social and news media suggested the possibility of some safety concerns about the vaccine, including increased risk for multiple sclerosis and similar diseases, according to background information with the study.
To investigate this possible risk, researchers led by Nikolai Madrid Scheller, of the Statens Serum Institute in Copenhagen, Denmark, examined data on nearly 4 million Danish and Swedish girls and women from 2006 to 2013. The participants ranged in age from 10 to 44 years.
Using national registers, the researchers analyzed information on HPV vaccination, diagnoses of multiple sclerosis and similar central nervous system disorders.
Of all the girls and women included in the study, approximately 789,000 received an HPV vaccine over the course of the review period, for a total of slightly more than 1.9 million doses.
Between 2006 and 2013, just over 4,300 of the participants were diagnosed with multiple sclerosis. Of these cases, 73 occurred within the two-year risk period for side effects after vaccination. The researchers also identified 3,300 cases of similar diseases, with 90 occurring within the two-year risk period.
The researchers concluded the HPV vaccine does not increase the risk for multiple sclerosis or similar diseases that cause damage to the protective covering -- called myelin -- that surrounds nerve cells.
The findings appear in the Jan. 6 issue of the Journal of the American Medical Association.
"Our study adds to the body of data that support a favorable overall safety profile of the [HPV] vaccine and expands on this knowledge by providing comprehensive analyses of multiple sclerosis and other demyelinating diseases," the study authors wrote.
They added that, given the size of the study population and the random use of nationwide registry data from Denmark and Sweden, it's likely that the findings are applicable to women in other countries.
There are two vaccines available to help protect against the sexually transmitted human papillomavirus (HPV) in the United States: Cervarix and Gardasil. Both vaccines are available for girls, but only Gardasil is available for boys, according to the U.S. Centers for Disease Control and Prevention.
The CDC recommends all boys and girls aged 11 and 12 get the three-dose vaccine so that protection is in place before they become sexually active.
The U.S. Centers for Disease Control and Prevention has more about the HPV vaccine.