Human Papillomavirus Recombinant Quadrivalent Vaccine, Types 6, 11, 16, 18 (Gardasil®) -Safety Update
The Centers for Disease Control and Prevention (CDC), and the FDA have sent out an update discussing the main concerns raised by healthcare professionals and consumers over the safety of Gardasil. The FDA and CDC report that surveillance to date has found Gardasil to be safe and effective.
There are several systems of monitoring vaccines and their potential adverse effects. The Vaccine Safety Datalink (VSD) and the Clinical Immunization Safety Assessment (CISA) Network are both collaborative efforts evaluating post-marketing adverse events. The FDA and CDC monitor vaccine adverse events through the Vaccine Adverse Event Reporting System (VAERS). The FDA and CDC evaluate reported adverse events to confirm or rule out potential new trends or side effects.
Over Sixteen million doses of Gardasil have been distributed in the United States. Of the 9,749 adverse events reported to VAERS (as of June 30, 2008) in patients who had received Gardasil, 6% were considered serious events. These included blood clots, Guillain-Barre Syndrome (GBS) and 20 overall deaths. At this time, there does not appear to be a causal relationship with the vaccine and these serious adverse events. Most patients who experience blood clots had other predisposing risk factors such as oral contraceptive use. Thromboembolic disorders continue to be monitored in VSD ongoing trials. Thus far, the GBS rate in vaccinated individuals does not indicate a causal relationship with the vaccine. There was no information linking the reported deaths with the vaccine. All adverse events will continually be evaluated by the FDA and CDC to detect any trends that may occur over time.
Additional information is available at the following links:
- CDC Vaccine Safety Information:
- FDA Information on Gardasil
July 25, 2008; University of Utah, Drug Information Service. Copyright 2008, Drug Information Service, University of Utah, Salt Lake City, UT.