HPV vaccine linked to more blood clot risk

ATLANTA, Aug. 19 (UPI) -- A human papillomavirus vaccine analysis found adverse events consistent with pre-licensing data except for fainting and blood clots, U.S. researchers say.

In 2006, the Food and Drug Administration licensed the quadrivalent human papillomavirus vaccine for females ages 9-26 to prevent infection with genital human papillomavirus types 6, 11, 16 and 18.

Dr. Barbara A. Slade of the Centers for Disease Control and Prevention in Atlanta and colleagues analyzed reports of adverse events following qHPV immunization received by the U.S. Vaccine Adverse Event Reporting System.

During the study period, the system received 12,424 reports of adverse events following immunization with qHPV -- an overall reporting rate of 53.9 reports per 100,000 vaccine doses distributed.

The analysis, published in the Journal of the Americans Medical Association, found that among the 12,424 adverse events, 772, or 6.2 percent, were serious, including 32 reports of death.

"The post-licensure safety profile presented here is broadly consistent with safety data from pre-licensure trials," the study authors said.