The cervical cancer vaccine Gardasil was approved by the FDA in June 2006. Human papillomavirus (HPV) has been shown to be responsible for many cases of cervical cancer. Gardasil prevents the development of cervical cancer by preventing HPV infection. This HPV vaccine was approved for use in females ages 9 to 26 years, and it is currently recommended that girls ages 11 to 12 years are vaccinated. Now that over 23 million doses of the vaccine have been distributed, it is easier to discern the common side effects and life-threatening conditions that may result after HPV vaccination.
Common Gardasil Side Effects
A recent analysis of HPV vaccine side effects was published in the Journal of the American Medical Association (JAMA). Researchers analyzed 12,424 reports of side effects following HPV vaccination. The most frequently reported side effects include the following:
- Partial or complete loss of consciousness
- Dizziness
- Nausea
- Headache
- Injection site reactions
Approximately 94% of the reported side effects were not considered to be serious.
HPV Vaccine Safety: Serious Side Effects
Approximately 6% of reported side effects were serious and included 32 reports of death. Medically important serious events included the following:
- Death
- Anaphylactic reaction
- Deep vein thrombosis
- Guillain-Barre Syndrome
- Hypersensitivity
- Transverse myelitis (inflammation across the width of the spinal cord)
- Inflammation of the pancreas
- Blood clot in the lung
- Convulsion
- Hives
- Autoimmune disorder
While these reported side effects are very serious, they did not occur very frequently. For example, for every 100,000 vaccines distributed, death occurred 0.1% of the time. Additionally, there is no evidence that directly links the HPV vaccine to each of the serious side effects reported. Therefore, the reported events may have only coincidentally followed vaccination.
Clinicians Interpret Reports of Cervical Cancer Vaccine Side Effects With Caution
Most of these HPV vaccine side effects were encountered in clinical testing of the vaccine, prior to licensing. However, fainting and deep vein thrombosis are two side effects that were not common during early clinical studies of the cervical cancer vaccine, and according to the report in JAMA, now appear to occur at higher-than-expected rates. However, most patients that experienced a blood clot had a known risk factor. In addition, Kenneth Alexander, MD, PhD, of the University of Chicago speculates that incidences of fainting in these young girls may be caused by fear of the needle, and not necessarily the vaccine itself.
This recent report that details the incidence of HPV vaccine side effects in a larger population of people enables women to more accurately weigh the risk of experiencing side effects from HPV vaccination against the risk of developing cervical cancer in the future.
References
Slade BA, et al "Postlicensure safety surveillance for quadrivalent human papillomavirus recombinant vaccine" JAMA 2009; 302(7):750-57.
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