Safety of human papillomavirus vaccine
At the request of the Strategic Advisory Group of Experts on immunization (SAGE), the Committee reviewed the safety of human papillomavirus (HPV) vaccines.
A review of available evidence of the safety of both the 4-valent HPV (Gardasil®) and the 2-valent HPV (Cervarix®) vaccines was presented. Data from pre-licensure randomized controlled trials and post-licensure surveillance reports from the 2 vaccine manufacturers as well as from the European Medicines Evaluation Agency, the United States Food and Drug Administration (FDA) and the United States Centers for Disease Control and Prevention (CDC) were included in the review.
The current evidence on the safety of HPV vaccines is reassuring. The reviewed data covered local and systemic events in short-term, and long-term events up to 6 years after vaccination, including pregnancy events. A common observation was the occurrence of injection site reaction and muscle pain. During adolescent vaccine campaigns, some mass sociogenic illnesses such as post-vaccination dizziness and syncope have been reported. These events have been prevented by observing adolescents for 15 minutes post-vaccination and encouraging good hydration. No concerns with the safety profile were identified.
As with the introduction of any new vaccine, it will be important to conduct surveillance to identify possible, rare unexpected adverse effects, especially as good-quality information on the rates of a variety of diseases before widespread vaccine introduction is generally lacking in the target age group for HPV vaccination (i.e. 9 to 26 years). Also, careful surveillance for specific adverse effects during pregnancy will be important as the target group includes females of reproductive age.
The Committee was advised of studies that are planned, mostly in developed countries, to monitor the occurrence of adverse effects of HPV vaccination. The Committee considered that it would be highly desirable if the protocols for these studies were to be made publicly available to encourage the conduct of similar studies in other locations, including developing countries. The evaluation of adverse effects, especially the long-term events and also the effectiveness of the HPV vaccine, would be greatly facilitated if national registers were maintained of all those who are vaccinated. This is planned in some countries, and the extension of this practice in other locations must be encouraged.