Gardasil Passes a 2-Year Safety Check
Safety Studies See No Sign of Safety Problems for HPV Vaccine
Oct. 22, 2008 -- Two years after Gardasil's approval, safety monitors detect no major safety problems with the HPV vaccine.
Gardasil protects against infection with dangerous strains of HPV, the sexually transmitted virus that causes cervical cancer and genital warts. The CDC recommends that girls get the vaccine at age 11 or 12 years -- long before they become sexually active.
A recent case series from Australia raised concerns that the vaccine might cause rare but serious side effects, including allergic shock and damage to the nervous system.
No such side effects can be linked to the vaccine, according to reports made at today's meeting of the Advisory Committee on Immunization Practices (ACIP), the independent panel of health experts that advises the CDC on U.S. vaccine policies. ACIP recommendations routinely become official U.S. policy.
The panel heard four reports on Gardasil's safety:
- The CDC's Vaccine Adverse Event Reporting System (VAERS) finds no link between Gardasil and adverse events reported by doctors and vaccine recipients.
- A continuous, week-by-week CDC analysis of data from eight managed-care organizations finds no sign of adverse events emerging in Gardasil recipients. This Vaccine Safety Datalink (VSD) project finds no "signal" linking Gardasil to eight safety problems, including blood clots, allergic reactions, stroke, seizure, or Guillain-Barre syndrome.
- An independent academic group, the Clinical Immunization Safety Assessment Network (CISA), finds no link between Gardasil and disorders of the central (transverse myelitis) or peripheral (or Guillain-Barre syndrome) nervous systems.
- Merck's registry of women who were inadvertently given Gardasil while pregnant finds no link between the HPV vaccine and birth defects, miscarriages, or infant/fetal deaths.
There have been reports of syncope -- fainting or loss of consciousness, sometimes resulting in hospitalization -- in teenage girls receiving Gardasil. A CDC analysis finds that syncope is on the rise among teenage vaccine recipients, but that the phenomenon is seen no more often with Gardasil than with all teen vaccines.
Matthew F. Daley, MD, associate professor of pediatrics at the University of Colorado, Denver, reported to the ACIP on a national survey of doctors' HPV vaccination practices.
The survey showed that 98% of pediatricians and 88% of family practitioners are administering Gardasil to their female patients. Nearly half recommend the vaccine for girls aged 11 to 12, while 82% recommended it by age 15.
About 30% of family practitioners and 18% of pediatricians said at least one in four parents refused HPV vaccination when they offered it to their 11- to 12-year-old girls. The parents had three major reasons for refusal:
- Parents worried that Gardasil is "too new."
- Parents said their teenage girl was too young or not sexually active.
- Parents said their insurance didn't cover Gardasil.
Most parents' concerns about Gardasil were not explicitly related to concerns about vaccine safety.