Let s say that you have gotten your first two HPV shots, but don t get your third, perhaps because you are stuck in Scotland waiting for the next appearance of the Loch Ness Monster. Or too busy wiping the BPA off your cash register receipts in order to prolong your life (these two are equally likely).
Fear not. Although not as good as three, two shots are vastly superior to none.
A recent study of the Karolinska Institute in Stockholm concludes that even two shots (three is the standard regimen) offer significant protection against condyloma (genital warts).
Lead author Lisen Arnheim-DahlstrÃ¶m, PhD and colleagues published a study in the Feb. 12 issue of the, which concluded that two shots provided 71 percent protection, as compared to 82 percent for those people who got all three shots.
The authors, who collected data on 1 million Swedish girls and women aged 10 to 24 during the time period of 2006 through 2010, caution that this does not constitute proof that two shots will provide protection against HPV-caused cancers, but it is not unreasonable to suspect that this will be true. Condylomas, although benign, may be the earliest manifestation of HPV-related cancers.
Experts in the field say that this should not be surprising.
Mark Einstein, MD, of Albert Einstein (no relation!) College of Medicine and Montefiore Medical Center in New York City said, [The two-dose effect seen by Arnheim-DahlstrÃ¶m and colleagues] just confirms how well these vaccines work. We know the natural history of warts is a quicker pace than precancerous cells on the cervix and certainly quicker than the development of cancer.
William Bonnez, MD, of the University of Rochester School of Medicine and Dentistry in Rochester, concurs: "It is reassuring to know that those girls who received at least two doses will likely get a substantial protection benefit.
He adds, "The demonstration in a population-based setting that vaccination will be effective against HPV-associated cancers will require a few more years, [although] experts have little doubt that it will eventually be seen.
ACSH s Dr. Gilbert Ross says, First of all, let me re-emphasize a plea for all eligible candidates boys and girls between ages 9 and 26 to get that HPV vaccine, preferably all 3 doses. It s the only vaccine we have against certain cancers. As for this study, it is reassuring that 2 doses are almost as protective as the full course against genital warts in girls. Since cervical cancer prevention was the key factor in getting any attention for the vaccine, the fact that it protects against warts is a main reason to get boys vaccinated too. I would bet that similar efficacy will be found for the abbreviated course among males as well.