To halt a spike in pertussis cases and deaths in infants, pregnant women now are advised to get a booster shot of the pertussis vaccine in their late second or third trimester. By a 14-1 vote, the US Centers for Disease Control (CDC) Advisory Committee on Immunization Practices (ACIP) recently recommended that women now be given a booster dose of Tdap after their 20th week of pregnancy.
Vaccination against pertussis cannot start before age two months, but this is the time when the disease is particularly deadly for unprotected infants. Of the 194 U.S. pertussis deaths from 2000 to 2009, 152 were in infants ages one month or less. Twenty-three deaths were in infants ages two to three months.
Doctors have been fighting recent outbreaks of whooping cough by giving the Tdap booster vaccine to women as soon as they give birth and also vaccinating everyone else who comes into contact with an infant. The idea, called “cocooning,” is good as an idea but in the real world, it’s been nearly impossible to vaccinate most fathers and even harder to find and vaccinate grandparents, siblings, and caretakers.
“Is cocooning working? No, not at the national level,” said CDC researcher Jennifer Liang, DVM. “We’ve had very little success vaccinating fathers and other family members.”
“We need a new strategy,” said ACIP working group chairman Mark Sawyer, MD, professor of pediatrics at the University of California, San Diego. The new strategy: give the Tdap booster vaccine to women in the late stages of pregnancy.
“It’s a twofer,” said ACIP chairwoman Carol Baker, MD, professor of pediatrics at Baylor College of Medicine, Houston. “By vaccinating in the late second or third trimester, you protect the mother and you protect the infant.” That’s because the developing fetus gets a protective dose of its mother’s antibodies. This protection can help bridge the gap between birth and the infant’s own vaccination.
The Tdap booster vaccine is meant for teenagers and adults. So for those who have already had their booster shot they do not need another but for those who are not sure, a second booster is safe.