Protect Infants Against Pertussis

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Pregnant women should receive a Tdap vaccine with every pregnancy, ideally between 27 and 36 weeks gestation, no matter how long it's been since her last Td or Tdap vaccine. Antibodies are expected to pass to the baby and provide protection as soon as the mother gives birth.

If mothers do not receive a Tdap vaccine during pregnancy and they have never been vaccinated, they should get vaccinated immediately after the baby is born. This may not protect the baby directly, but it may prevent the mother from becoming infected and passing pertussis to her baby.

All adults and adolescents at least 11 years old who have not received a Tdap vaccination should be vaccinated at least two weeks before coming into close contact with a newborn. This includes, for example, fathers, siblings, grandparents, caregivers, and healthcare professionals. Creating a circle of protection around the baby is called "cocooning."

Everyone 11 years and older should receive one dose of Tdap, regardless of contact with infants.

The Explanation for the Recommendations

Infants less than 12 months old, especially infants less than three months old, are most likely to die from a pertussis infection. Infants younger than six weeks old should not receive the pertussis vaccine. Infants are vaccinated at 2, 4 and 6 months of age but are not well protected until the series is complete. A booster is recommended around 15 months and at the age of 4.

If a woman is vaccinated during pregnancy, she will likely not spread pertussis to her newborn child. Giving Tdap to the mother between 27 and 36 weeks gestation makes antibodies pass to the baby. Studies have shown that maternal vaccination likely protects infants from being infected or, at least, having severe pertussis.

• 4 out of 5 infants who contracted pertussis in the U.S. in recent years got it from someone who lived with them (when a source was identified).
• The body's immune response peaks two weeks after Tdap is administered. If a mother is vaccinated after the baby is born, there are still two weeks after birth when the mother and infant are susceptible to infection. So, although an expecting mother should get vaccinated during pregnancy, getting it after the baby is born will still provide some protection.

Regarding Tdap vaccination during pregnancy, the CDC Advisory Committee on Immunization Practices found that:

• Tetanus vaccines have been safely given to pregnant women since the 1960s.
• There are not more or unusual side effects in pregnant women.
• There is no harm to the fetus.

Babies can receive their first dose of pertussis vaccine at two months, but they are at risk for serious complications from pertussis before that age. Most infants are not completely protected until they have had three doses (at 2, 4, and 6 months of age).