Girls between the ages of 11 and 12 should be vaccinated against the human papillomavirus (HPV) before they become sexually active, according to recommendations released Monday by the American College of Obstetricians and Gynecologists (ACOG).
The recommendations, published in the group's journal Obstetrics & Gynecology, back existing U.S. government guidelines.
They also call on gynecologists and obstetricians to discuss HPV vaccination with older girls and young women — an age group that they are more likely to treat compared with the 11- to 12-year-old range.
According to ACOG, girls and women between the ages of 13 and 26 who have not yet received the HPV vaccine should get "catch-up" doses — also in line with government recommendations.
There are more than 100 strains of HPV, some of which cause genital and anal warts. In most people, the immune system clears the infection fairly rapidly. However, persistent infection with certain HPV strains can eventually lead to cancer in some cases.
Persistent HPV infection is the primary cause of cervical cancer, and it can also lead to cancers of anus and penis.
There are two vaccines that can prevent infection with certain cancer-related strains of HPV: Merck's Gardasil and GlaxoSmithKline's Cervarix, each of which cost just under $400 for a three-dose series. In the U.S., the vaccines are approved for girls as young as 9, and young women up to the age of 26. Last year, regulators approved Gardasil for boys and men in the same age group.
"The ideal time for girls to receive the HPV vaccination is before they become sexually active and become exposed to HPV," Dr. Diane F. Merritt, chair of ACOG's Committee on Adolescent Health Care, said in a written statement.
"For this reason, we recommend that girls get vaccinated by age 11 or 12 and possibly as early as age 9, depending on risk factors."
ACOG's committee does not recommend one vaccine or the other, but notes in its guidelines that Cervarix does not protect against genital warts caused by two HPV strains that are low-risk for cancer.
Girls and young women who are already sexually active should still be vaccinated, according to the ACOG and government recommendations. That includes those with a history of genital warts or abnormal growths in the cervix called cervical intraepithelial neoplasia — though, ACOG says, doctors should be sure to point out that the HPV vaccine may not be as effective for these patients.
Pregnant women should not receive the vaccine, since its safety during pregnancy has not been established, but mothers who are breastfeeding can be vaccinated, according to ACOG — again, echoing government guidelines.
So far, the HPV vaccine, which is given in three doses over six months, appears to be largely safe.
According to the Centers for Disease Control and Prevention, as of last May 31, nearly 30 million doses of Gardasil had been distributed in the U.S. And as of that date, the agency's Vaccine Adverse Event Reporting System (VAERS) had received just over 16,000 reports of "adverse events" in patients who had been given the vaccine.
Of those, 92 percent were considered "non-serious," and included problems such as pain and swelling at the injection site, headache, nausea and fainting. The rest were serious and included blood clots, a rare disorder called Guillain-Barre syndrome that causes muscle weakness, and 29 confirmed deaths among vaccine recipients.
However, no unusual or common patterns have been found to suggest that the vaccine itself caused those medical problems or deaths, according to the CDC.
Cervarix was just licensed in October 2009, and as of May 31, 2010, the CDC had received only a few reports of side effects. Anyone, including doctors and the general public, can report side effects to VAERS.
SOURCE: http://link.reuters.com/tyx58m Obstetrics & Gynecology, September 2010.