Study checks necessity of 3-shot HPV vaccine

The human papillomavirus or HPV vaccine is a three-dose course of shots recommended for teenagers before they become sexually active. The vaccine can protect against cervical cancers in women and against genital warts and other cancers in people of both sexes.

New research, published in the Journal of the American Medical Association, questions whether two shots can provide the same level of protection as the standard three-shot vaccine. 

The current standard calls for two shots to be given about a month apart, followed by a third shot about six months later.

Keyana Bjornson, 17, participated in the JAMA study. 

"My parents had explained that it will help prevent cancer for when I'm older," she said. "I thought it would also help benefit other girls later on so I thought it was a good choice."

Researchers found that girls who got two shots showed the same results as those who got three.

"Two doses in girls is certainly enough to start with, but it doesn't answer the question whether that's going to be enough to get women through the peak young adult years when they are most likely to meet HPV," said Dr. Simon R.M. Dobson, of the University of British Columbia.

Further studies are necessary to determine if a booster third dose is needed. Researchers say until more research is done, there is not enough information to be able to recommend a change to the standard dose schedule.

The HPV vaccine is expensive, so eliminating a third dose may encourage more use of it around the world.