Oct. 24, 2012 -- Women should get a Tdap shot during every pregnancy to protect their infant from whooping cough, even if they have had Tdap shots before, new guidelines advise.
Today's recommendation comes from the CDC's Advisory Committee on Immunization Practices (ACIP), the panel that sets U.S. vaccination policy.
The new shot recommendation is meant to protect newborns from pertussis, better known as whooping cough.
Pertussis kills babies, particularly those under 2 months of age. So far this year, at least 16 U.S. infants have died of pertussis. But that's just "the tip of the iceberg," Baylor University pediatrician Carol Baker, MD, told the panel.
"I take care of babies who die of pertussis," said Baker, a former chair of the ACIP. "The official number of confirmed pertussis deaths is small. But these children die of apnea [inability to breathe], and a large number of SIDS [sudden infant death syndrome] deaths are probably pertussis."
Babies are vulnerable because they can't start vaccination against pertussis until they're 2 months old.
Previously, there was an effort to protect infants by making sure everyone around them was vaccinated. This "cocooning" strategy isn't working, the CDC's Jennifer L. Liang, DVM, told the ACIP. Too few people were getting their booster shots.
"Cocooning is an insufficient strategy to prevent pertussis in infants," Liang said.
Instead, the ACIP considered a new strategy: Vaccinate pregnant women. Protective anti-pertussis antibodies cross the placenta to the fetus, protecting newborns until they can make antibodies of their own. The optimal time to get the Tdap vaccine during pregnancy is between 27 and 36 weeks gestation.
Is it safe? The Tdap vaccine has three components. It protects against tetanus and diphtheria as well as against pertussis. Healthy adults given repeat doses don't have a problem with getting two shots in two years, except that their arms tend to be sorer, and sore longer, than after the first shot.
The vaccine is known to be safe in pregnant women, and experts who testified before the ACIP suggested that the vaccine would be safe when repeat doses are given with each and every pregnancy.