Study Suggests Two Doses of HPV Vaccine With Booster Could Be as Effective as Three Doses Together

May 2, 2013 —Administering two doses of the human papillomavirus vaccine appears to produce an antibody response similar to the current three-dose method, according to a study published on Wednesday in the Journal of the American Medical Association, MedPage Today's "The Gupta Guide" reports.

The study involved 520 girls and women in Canada. Participants ages nine to 13 received either two or three doses of Merck's Gardasil HPV vaccine, while those ages 16 to 26 were given three doses.

One month after the last dose was administered, researchers found that participants given two doses had just as many antibodies against HPV as those who received three doses.

Two to three years later, antibody levels among the younger participants who received two doses were the same as those for the older participants who received three doses. However, antibodies were higher among the younger three-dose group than their peers who received two.

Implications

The authors recommended that girls could receive two doses in early adolescence, followed by a booster administered in late adolescence "to provide a high level of antibody through early adulthood." They noted that this already is the provisional practice in Quebec and British Columbia.

In an accompanying editorial, Jessica Kahn and David Bernstein -- both of the Cincinnati Children's Hospital Medical Center -- wrote that a two-dose approach could make the vaccine more affordable, but they noted that the study lacked data on clinical outcomes (Gever, "The Gupta Guide," MedPage Today, 4/30).