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The
Associated Press
- A new study has found that giving a booster shot in
addition to the oral polio vaccine is the best way to
ensure that babies in Third World countries are protected
from the virus.
In
industrialized countries, three doses of oral vaccine
are 95 percent effective in protecting children. But the
rate in developing countries is as low as 65 percent,
perhaps because youngsters there are resistant to the
vaccine or the vaccine is not properly refrigerated.
In
a study, researchers gave either booster shots or extra
doses of an oral vaccine to 785 9-month-old babies in
Oman who had already gotten five doses of oral vaccine.
Only the booster shots proved effective.
The
booster shots kept antibody levels high for at least six
months, Dr. Roland W. Sutter of the Centers for Disease
Control and Prevention reported in Thursday's New England
Journal of Medicine.
The
polio vaccine works by spurring the immune system to make
protective antibodies. Polio shots contain dead polio
virus; the oral vaccine contains a live but weakened virus.
Although
it has been nine years since the last case of polio in
the Western Hemisphere, the virus is still found in 30
countries in South Asia and sub-Saharan Africa.
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