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A new study suggest that the HPV vaccine given to girls to protect against cervical cancer, may only need one dose instead of the recommended three doses in order to provide long-term protection.  

"Vaccination with two or even one vaccine dose could simplify the logistics and reduce the cost of vaccination in the developing world, where more than 85 percent of cervical cancer occurs and it is the most common cause of cancer death in women," study author Mahboobeh Safaeian, an investigator in the NCI's division of cancer epidemiology and genetics, said in Healthday.

"More than 275,000 women die from cervical cancer each year worldwide, making it the sixth-leading cause of cancer death, according to the World Health Organization," reported Healthday. 

For the study, researchers examined the effectiveness of Cervarix, an HPV vaccine, women in Costa Rica were treated with. 

Researchers measured the immune response to the vaccine by taking blood samples from 78, 192, and 120 who received one, two and three doses of it.
Physicians then compared the data to that from 113 women who had been infected with HPV before because they were not vaccinated. 

Researchers found, "Up to four years later, all of the women in all three vaccination groups had antibodies for HPV 16 and 18, the two strains Cervarix guards against," reported Healthday. "Moreover, the levels of antibodies in women from the one- and two-dose groups were between five and 24 times higher than the levels of antibodies in women who were not vaccinated but were infected with HPV."

Researchers suggest that even though the levels of antibodies were lower among those who received one dose versus those who were treated with three, the levels were effective in preventing the disease which provides new insight into treatment. With these findings, researchers want to continue to examine data. 

"We need to set up some sort of surveillance system for those who only got one or two doses," Debbie Saslow, director of breast and gynecologic cancer for the American Cancer Society said. "If we're identifying those girls, let's see if we can follow them. We don't need to start a big randomized trial. We can look back using medical records." 

The findings are published in the journal Cancer Prevention Research.