Tuesday, June 1, 2010

CDC Confirms Efficacy of HPV Vaccine in Men

The Centers for Disease Control and Prevention (CDC) confirmed its provisional recommendation from 2009 that Gardasil (Human papillomavirus (HPV) vaccine from Merck) is both efficacious and safe against HPV infection in boys and young men ages 9 to 26, and helps protect against 90% of genital warts cases.

Gardasil was approved by the Food and Drug Administration (FDA) in 2006 for use in females from age 9 to 26 to prevent cervical cancer and genital warts. Soon after, the CDC's Advisory Committee on Immunization Practices (ACIP), which helps to set the US's vaccination policies, recommended that Gardasil become part of routine vaccination for all girls 11 to 12 years old.

Recently, there were concerns about the safety of Gardasil. The CDC reported as of June 1, 2009, over 25 million doses of Gardasil, have been distributed in the U.S. and there was an average of 53.9 Vaccine Adverse Events (VAEs) reports per 100,000 vaccine doses. Of these, 40 percent occurred on the day of vaccination, and 6.2 percent were serious, including 32 reports of death.
Other controversies have arisen, which are summarized nicely in this link.
Last year, the ACIP added males to the list of who can benefit from Gardasil vaccination, but did not advise routine immunization. (The advice was specific to Gardasil and did not apply to the second HPV vaccine approved by the FDA, in 2009, called Cervarix, since that vaccine targets only the cancer-causing strains of HPV and not the strains primarily responsible for genital warts.) Health officials say that the HPV burden (both genital warts and cervical cancer) is heaviest in females. Therefore if herd immunity is established in the female population, this would decrease the HPV cases drastically in boys. They also stated that it would not be cost effective to push for vaccination of boys.

The CDC confirmed that while safe and efficacious in males, the HPV vaccine should not become part of the regular vaccination schedule. The recommendation remains vague on exactly how the vaccine should be used in men, and which males could benefit, stating only that the vaccine “would be most effective when given exposure to HPV through sexual contact.” More detailed advice on the use of HPV in specific, higher risk populations may be forthcoming, say CDC scientists, since the FDA is currently reviewing additional data on the vaccine's ability to prevent precancerous growths among men who have sex with men.

Lance D. Presser has a PhD in Microbiology & Immunology, and is a Public Health Laboratorian.

1 comment:

  1. Just an update on Gardasil, Merck is pushing for a bump in max age limit to 45. The full story below.