By the way, doctor: Should I get the HPV vaccine if I'm already infected?
Q. I'm 26 and positive for HPV. Is there any point in my getting the new HPV vaccine?
A. There are 30 to 40 strains of sexually transmitted human papillomavirus (HPV). The vaccine Gardasil targets the four strains most closely linked to cervical cancer and genital warts. For women not already infected with these strains, Gardasil is almost 100% effective at preventing genital warts and cancerous or precancerous lesions of the cervix. That's why public health officials recommend that girls ages 11 to 12 be vaccinated — before they become sexually active.
But the vaccine also offers some protection for HPV-positive women, reducing cervical lesions by 17% and genital warts by 35%. HPV-positive women usually aren't infected with all four of the targeted strains. In clinical trials, those infected with one or more of these strains before vaccination were protected against the remaining ones.