Cervarix™, an investigational cervical cancer vaccine intended to protect against infection with two high-risk types of human papillomavirus (HPV), may provide protection to older as well as younger women. These results were presented at the 2006 annual meeting of the American Society of Clinical Oncology (ASCO).
HPV types 16 and 18 account for roughly 70% of all cases of cervical cancer. Cervarix (a bivalent L1 virus-like particle vaccine) is intended to prevent infection with these high-risk types of HPV, and may also offer some protection against two other high-risk types of HPV-types 45 and 31.
Because infection with HPV generally occurs soon after an individual becomes sexually active, vaccination at a young age–before sexual activity begins-is likely to offer the greatest protection. Some older women could also benefit, however, if they have not yet been infected with the types of HPV covered by the vaccine, and if they produce an effective immune response to the vaccine.
To explore the immune response to the vaccine in a broad age range of women, researchers conducted a study among 666 women in Germany and Poland. Women were between the ages of 15 and 55 years. The vaccine was given in three doses over a six-month period. Immune response was evaluated by looking at antibody levels against HPV 16 and HPV 18.
- Following vaccination, all women had detectable antibodies to HPV types 16 and 18. Furthermore, antibody levels were several times higher than would be expected after natural infection with HPV.
- Although antibody levels declined with age, the levels observed in the oldest women were still expected to provide protection from infection.
This study suggests that Cervarix may protect against infection in older as well as younger women. GlaxoSmithKline, the maker of Cervarix, is expected to submit an application for approval of Cervarix to the U.S. Food and Drug Administration (FDA) by the end of 2006.
Reference: Schwarz TF. An AS04-containing Human Papillomavirus (HPV) 16/18 Vaccine for Prevention of Cervical Cancer is Immunogenic and Well-tolerated in Women 15-55 Years Old. Proceedings of the 42nd annual meeting of the American Society of Clinical Oncology. Atlanta, Ga. June 2006. Abstract # 1008.