More Evidence That HPV Vaccine Shields Against Cervical
WEDNESDAY, Nov. 9 (HealthDay News) -- A new study suggests that
the Cervarix cervical cancer vaccine may provide "excellent"
protection against a precancerous lesion that is often a forerunner
to invasive cervical cancer.
Cervarix, made by GlaxoSmithKline, protects against human
papillomavirus (HPV) types 16 and 18, which cause 70 percent of
cervical cancers. The vaccine is particularly effective when given
to adolescent girls before they become sexually active.
Cervarix is one of two HPV vaccines approved by the U.S. Food
and Drug Administration, the other being Merck's Gardasil.
The four-year study included nearly 20,000 women aged 15 to 25
in 14 countries in North America, Latin America, the Asia-Pacific
region and Europe. The vaccine was found to be more than 93 percent
effective against the CIN3 lesion, a precancerous anomaly that
often appears before invasive cancer.
The vaccine was 100 percent effective against cancer in young
women who were not infected with HPV before they were immunized,
the study found, and it was 46 percent effective against CIN3 and
77 percent effective against cancer in the general population of
women (who may or may not have been previously exposed to HPV).
Cervarix was 100 percent effective against CIN3 lesions
specifically linked to the HPV 16 and HPV 18 strains in previously
unexposed women, and it was nearly 46 percent effective in the
The study appears online Nov. 8 in
The Lancet Oncology.
One expert said the new findings "are further evidence of the
benefits of HPV vaccine."
Dr. Stephanie V. Blank, an assistant professor in clinical
gynecologic oncology at NYU School of Medicine, said, "Although not
perfect, this study is the largest trial of HPV 16/18 vaccine to
date. It is significant because with longer time of follow-up, we
are better able to show the true effect of the vaccine."
Blank added that the study "shows that the HPV vaccine will be
most protective among adolescent girls but that it is also
effective among HPV-exposed women."
Along with specifically targeting HPV 16 and 18, Cervarix also
partially protects against four other types of HPV (31, 33, 45 and
51) that account for 15 percent of cervical cancers, according to
another study in the same issue of the journal.
Increasing vaccination rates, particularly among young females
who aren't sexually active, should be a focus of HPV vaccination
efforts, Dr. Mark Schiffman and Sholom Wacholder of the U.S.
National Cancer Institute stressed in an accompanying
Blank agreed with that assessment. "There are several take-home
messages here: Vaccinate early; catch-up programs are also worth
it; the positive impact of the HPV vaccine may be even more than we
had expected; and the vaccine has an effect even if a woman is
already exposed to HPV," she said.
The U.S. National Cancer Institute has more about
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