Home' Trinidad and Tobago Guardian : June 22nd 2013 Contents A28
body & soul
Guardian www.guardian.co.tt Saturday, June 22, 2013
A vaccine against a cervical cancer virus cut
infections in teen girls by half in the first study to
measure the shot s impact since it came on the
market. The results impressed health experts and
a top government health official called them strik-
The research released Wednesday echoes studies
done before the HPV vaccine became available in
2006. But the new study is the first evidence of just
how well it works now that it is in general use.
Only about half of teen girls in the US have gotten
at least one dose of the expensive vaccine, and just
a third of teen girls have had all three shots, according
to the latest government figures.
"These are striking results and I think they should
be a wake-up call that we need to increase vaccination
rates," said Dr Thomas Frieden, director of the Centers
for Disease Control and Prevention.
Cervical cancer is caused by certain types of the
common sexually transmitted virus called HPV, for
The vaccine, which costs about US$130 per dose,
protects against a few of those strains, including two
blamed for 70 per cent of cervical cancers. The shots
work best if given before someone is sexually active
so the emphasis has been on giving the shots to 11-
and 12-year olds.
The CDC study compared infection rates in girls
ages 14 to 19 before and after the vaccine became
available. The proportion infected with the targeted
HPV strains dropped 56 per cent, from about 12 per
cent before the vaccine was sold to five per cent.
That result was for all teens after it was on the market,
whether or not they were vaccinated.
Among girls who had gotten the vaccine, the drop
in HPV infections was higher---88 per cent.
There are two vaccines against HPV, but the study
mainly reflects the impact of Gardasil, the Merck &
Co vaccine that came on the market in 2006. A
second vaccine approved in 2009---GlaxoSmithKline s
Cervarix---probably had relatively little bearing on
the results, said the CDC s Dr Lauri Markowitz, the
study s lead author.
Both vaccines are approved for use in males and
females---in ages nine to 26 for females, and nine to
21 in males. The vaccine was only recommended for
boys in late 2011, and the CDC has not yet reported
data on how many boys have gotten the shot since
then. HPV vaccination requires three shots over six
An estimated 75 to 80 per cent of men and women
are infected with HPV during their lifetime. Most
don t develop symptoms and clear it on their own.
But some infections lead to genital warts, cervical
cancer and other cancers. The study didn t look at
cervical cancer rates. It can take many years for such
cancers to develop, and not enough time has passed
to know the vaccine s impact on cancer rates, CDC
The study involved interviews and physical exam-
inations of nearly 1,400 teen girls in 2003 through
2006 and of 740 girls in 2007 through 2010.
The vaccine s impact was seen even though only
34 per cent of the teens in the second group had
received any vaccine. That could be due to "herd
immunity"---when a population is protected from an
infection because a large or important smaller group
Only about 20 per cent of those vaccinated got all
three doses. That result will likely feed an ongoing
discussion about whether all three doses are necessary,
Overall, the study found no significant change over
time in the proportion of teens who d ever had sex
and in those who had multiple sex partners. However,
it did find that a higher percentage of vaccinated
teens said they d had three or more sex partners.
That could have driven down infection rates,
YOUR DAILY HEALTH
News and Advice
The new study is the first evidence of just how well the vaccine works now that
it is in general use. PHOTO COURTESY CONNECT WITH WELLNESS
HPV vaccine cut infection
by half in teen girls
Markowitz noted, if the teens who got vaccinated
were the ones at highest risk of getting an infection
and spreading it.
The research was released online by the Journal
of Infectious Diseases. (yahoo.com)
Links Archive June 21st 2013 June 23rd 2013 Navigation Previous Page Next Page