HPV protection may require fewer shots
NEWS IN BRIEF — Posted May 13, 2013
Two doses of the human papillomavirus vaccine might offer a similar level of protection for young women as three doses, said a study in the May 1 issue of The Journal of the American Medical Association.
Researchers found that females who received two doses in six months had similar immune responses to HPV-16 and HPV-18 as girls who got three doses during the same period. Those two genotypes account for 70% of cervical cancer cases in the U.S., said the Centers for Disease Control and Prevention.
But the study authors said more data are needed on the duration of protection of two doses before reduced-doses schedules can be recommended (link).
Each year, an estimated 12,000 U.S. women are diagnosed with cervical cancer, and about 4,000 die of the disease, according to the CDC. To help prevent such deaths, the agency recommends that 11- and 12-year-old girls and boys receive three doses of the HPV vaccine.
Barriers to completing the immunization series in the U.S. and other countries include the number of recommended doses and the high cost of the vaccine, the study authors said.
Researchers examined data between August 2007 and February 2011 on 830 Canadian females ages 9 to 26 who had four or fewer sexual partners in their lifetimes. Participants were randomized to receive either two or three vaccine doses during a six-month period. Their antibody levels were measured at the start of the study and then at 7, 18, 24 and 36 months.
The study was published in a JAMA theme issue on child health, which included reports on vitamin D and the impact of early childhood adversity on a youth’s health and adult life.