ROANOKE TIMES
Copyright (c) 1996, Roanoke Times
DATE: Monday, December 2, 1996 TAG: 9612020125
SECTION: NATIONAL/INTERNATIONAL PAGE: A-5 EDITION: METRO
DATELINE: WASHINGTON
SOURCE: Associated Press
A Harvard physician has developed a vaccine that one day could protect thousands of babies from a potentially deadly infection that mothers now try to avoid by taking powerful antibiotics during childbirth.
The threat is group B streptococcus, a bacterium that lurks harmlessly in many women's bodies but that can be fatal or brain-damaging if passed to infants in the birth canal.
The National Institutes of Health plans to immunize some pregnant women late next year in studies designed to prove the vaccine is safe enough - and works well enough - to administer to millions of women.
``We know exactly what the vaccine should look like and how to make it,'' Harvard professor Dr. Dennis Kasper said. ``Now it's a matter of going through the testing so it can save babies' lives.''
About 30 percent of U.S. women harbor Group B strep, a cousin of the bug that causes strep throat. Childbirth infects one in 500 of America's about 4 million newborns every year. Ten percent die, and up to half suffer long-term damage from seizures to mental retardation.
Dozens of other babies catch a slightly less fatal ``late-onset'' form of Group B strep from less intimate contact with infected adults when they're weeks old.
Last spring, the national Centers for Disease Control and Prevention advised obstetricians to give penicillin to all women at risk of strep when they give birth. More than 1 million women may get treated each year, but even such widespread therapy can't help all babies.
``We estimate in the best case, our approach will prevent 85 percent'' of infections during childbirth, said CDC epidemiologist Dr. Anne Schuchat. In addition, ``I've spoken to many mothers who lost babies to late-onset disease'' who don't understand that antibiotics during delivery simply couldn't help.
A vaccine would prod a mothers' immune systems to send antibodies across the placenta and provide newborns with strep protection for a few months until the babies' own immune systems to kick in.
Kasper created the vaccine using the sugar coating that encapsulates Group B strep, enabling the body to recognize the bacteria without causing disease.
This first vaccine proved very safe for pregnant women but was too weak. It took Kasper another decade to show that adding a version of the tetanus vaccine - an immunization pregnant women already receive - to his initial strep vaccine boosted its effectiveness.
In a study in this month's Journal of Clinical Investigation, Kasper gave the strengthened vaccine or the old, weaker one to 100 women in Houston who were not pregnant. More than 90 percent who received the new vaccine made significant antibodies against strep, vs. a 60 percent response to the old vaccine.
``The work is very promising,'' said Pamela McInnes, chief of strep research at the National Institutes of Health, which financed Kasper's work.
LENGTH: Medium: 59 linesby CNB