Quadrivalent human papillomavirus (HPV) vaccine: a review of safety, efficacy, and pharmacoeconomics.

WHAT IS KNOWN AND BACKGROUND

The introduction of vaccines has lead to a significant reduction in morbidity and mortality from diseases such as measles, rubella and poliomyelitis, as well as the eradication of smallpox (Ertl HC, Xiang Z (1996) The Journal of Immunology, 156, 3579-3582). A recent vaccine approved by the Food and Drug Administration (FDA) is the recombinant quadrivalent human papillomavirus (HPV) vaccine (Merck, Gardasil®). Concerns raised with this preventive measure include safety and efficacy issues as well as the financial implications. Furthermore, the use of the vaccine in women outside the currently approved age ranges and in adolescent boys and men has also been a source of debate.

OBJECTIVE

A review of two licensed HPV vaccines (Gardasil, Merck and Cervarix, GalxoSmithKline) in the light of these issues.

METHODS

Literature searches were conducted using the MEDLINE (1966-December 2008) and PubMed databases in addition to the Centers for Disease Control and Prevention website. Bibliographies of selected references were also evaluated for relevant articles. Published guidelines and press releases were utilized as were the manufacturer's package inserts. The collection of information for this review was limited to the most recently available human data.

RESULTS AND DISCUSSION

The HPV quadrivalent vaccine has been effective in the management of HPV by preventing vaccine subtype-related persistent infection and precancerous lesions as evidenced by numerous clinical trials. It is also regarded as a generally safe and well-tolerated vaccine, based on an assessment of reported adverse events submitted through governmental databases and analyzed by independent researchers. The majority of adverse events were non-serious and the vaccine has not been conclusively implicated with serious events. The FDA continues to focus on routine post-marketing surveillance monitoring of reported adverse events. The bivalent vaccine has also been shown to be effective in reported trials. Its adverse effect profile also appears acceptable.

WHAT IS NEW AND CONCLUSION

The HPV vaccines appear safe and effective. Additional clinical research on the vaccines on women outside the currently approved age ranges and in males is necessary. Studies on longer-term outcomes, including cervical cancer and the emergence of new viral genotypes are also necessary.