Source: professional.cancerconsultants.com
Author: staff

Researchers affiliated with the GlaxoSmithKline Vaccine HPV-007 Study Group have reported that Cervarix® [human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine] has “high and sustained immunogenicity, and a favorable safety” profile for up to 6.4 years following administration. The details of this study appeared in an early online publication in the Lancet on December 3, 2009.[1]

Cervarix is approved by the U.S. Food and Drug Administration for the prevention of cervical pre-cancers and cervical cancer associated with HPV types 16 and 18. It is approved for use in girls and women between the ages of 10 and 25 years.

Human papillomaviruses consist of more than 100 different viruses. Some types of HPV cause warts on the hands or feet; others cause genital warts; and some have been linked with cancer, most notably cervical cancer. The types of HPV most commonly linked with cervical cancer are HPV 16 and HPV 18, but several other high-risk types contribute to cancer as well.

The types of HPV that cause cervical cancer or genital warts are transmitted sexually. HPV infection is extremely common and generally occurs soon after an individual becomes sexually active. Although most infections resolve on their own, some persist and can lead to precancerous or cancerous changes to the cervix, vulva, vagina, penis, and anus. HPV infections have also been linked with some head and neck cancers.

The first HPV vaccine to be approved in the United States was Gardasil®, which protects against HPV types 6 and 11 (linked to genital warts), as well as the cancer-associated types 16 and 18. Cervarix also protects against HPV types 16 and 18. Both Gardasil and Cervarix are intended to prevent infection with certain types of HPV and do not treat existing HPV infections or cervical abnormalities. It’s also important to keep in mind that these vaccines do not protect against all types of HPV; women who are vaccinated should continue to be screened for cervical cancer.

The current report presents the results of follow-up analyses of young women participating in two randomized controlled trials of Cervarix for prevention of cervical cancer with follow-ups extending to 6.4 years. These authors reported that prevention of HPV 16/18 was 95.3% and prevention of persistent infection was 100%. Cervarix was 100% effective in preventing cervical intraepithelial neoplasia (CIN) 2+ associated with HPV 16/18in young women. Cervarix was 72% effective in preventing lesions independent of HPV DNA. They also reported that antibody concentrations remained 12 times higher than in control women. There were also no more side effects to the vaccine than to the placebo.

Comments:
This is important information, as durability of vaccination is a necessity for application to underdeveloped countries, where the risk of cervical cancer is the highest. An accompanying editorial suggests that this new information provides an impetus to develop methods to vaccinate more young women before sexual activity in order to prevent the 0.5 million new cases of cervical cancer that occur worldwide each year.[2]

References:
[1] The GlaxoSmithKline HPV-007 Study Group. Sustained efficacy and immunogenicity of the human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine: analysis of a randomised placebo-controlled trial up to 6.4 years. Lancet [early online publication]. December 3, 2009.

[2] Clifford GM. Global access to HPV vaccination: what are we waiting for? Lancet [early online publication]. December 3, 2009.