Cervical Cancer Vaccines: More Promise
New Studies Show Broader, Longer Protection in Vaccines' Trials
Gardasil & Women With HPV Exposure
Daron Ferrris, MD, of the Medical College of Georgia in Augusta, studied a subset of the nearly 18,000 women who participated in the Gardasil vaccination trials.
Ferris focused on more than 4,700 women who had previous exposure to at least one of the HPV types covered by Gardasil, following them for an average of two years.
During that time, Gardasil was "100% effective" in protecting against cancerous and precancerous lesions and "highly effective" in preventing genital warts and vaginal and vulvar lesions in those women, Ferris writes.
Ferris' findings were presented in Paris at the European Research Organization on Genital Infection and Neoplasia's sixth international multidisciplinary congress.
Cervarix: More Than 4 Years of Protection?
Cervarix may be effective for more than four years, states a study in The Lancet.
The researchers included Diane Harper, MD, of New Hampshire's Dartmouth Medical School. Harper and colleagues followed about 800 women who had participated in a 2003-2004 Cervarix study conducted in the U.S., Canada, and Brazil. Participants either got three doses of Cervarix or a placebo on the same dosing schedule used in the Gardasil trials.
The women who got Cervarix continued to have high levels of antibodies against the HPV types targeted by Cervarix -- HPV types 16 and 18 -- "for up to 4.5 years," write Harper and colleagues.
The researchers also found some evidence that Cervarix may also protect against infection with HPV types 45 and 31. However, Harper's team notes that a high frequency of multiple infections complicated those analyses and that the vaccine hasn't shown protection against HPV types beyond types 16 and 18 in other trials.
Merck funded both Gardasil studies. The Cervarix study was funded by GlaxoSmithKline Biologicals.