Cervical Cancer Vaccine Approved
FDA Approves Gardasil for Girls and Women Aged 9-26
WebMD News Archive
Effective and Safe continued...
To be effective, Gardasil must be given in three doses over six months (the
second dose is given two months after the first; the third dose six months
after the first). It's not yet clear whether a person will receive lifelong
immunity. In tests checking for presence of the virus so far, the vaccines
remain protective for four years and counting. For preventing vaginal and
vulvar cancer, the vaccines have been
protective for at least two years.
The wholesale price for Gardasil will be $120 per dose; $360 for all three
There's a second vaccine in the works: Cervarix, from GlaxoSmithKline.
Cervarix targets only two HPV strains, HPV-16 and HPV-18, the ones most
commonly linked to cancer as opposed to genital
warts. GlaxoSmithKline says it plans to seek FDA approval for Cervarix
by the end of the year. Early studies find that this vaccine, too, is extremely
safe and effective.
Both Merck and GlaxoSmithKline are WebMD sponsors.
Pap Screening Still Needed
Despite its potency, Gardasil won't prevent every cervical cancercervical cancer or every HPV infection. There
are some 100 HPV strains out there. Those covered by the vaccine are the worst
offenders, but not the only ones.
Neither Gardasil nor Cervarix prevent disease in people already infected
with the virus. Perhaps as many as 80% of adults have been exposed to at least
one strain of HPV, Kahn says. For reasons not fully understood, only a minority
of people with HPV get cervical cancercancer or wartswarts.
"These vaccines only prevent infection. They do not prevent disease once you
are already infected with the virus," Kahn says. "The vaccines do not treat
This means that while the vaccines undoubtedly will prevent many of the
annual 3,700 U.S. and 233,000 worldwide cervical-cancer deaths, it will not end
cervical cancer, genital
wartsgenital warts, or
the spread of other HPVs.
"One of the points I am going to try to get across to teens is to
stressstress that even after getting the
vaccine, they must continue to get regular Pap screening," Kahn says. "Some
vaccinated women will still have abnormal Pap tests. It does not mean the
vaccine is not working. A lot of abnormal Paps are caused by HPVs that are not
in the vaccines."