Pertussis (Whooping Cough)

Pertussis is a continuing threat to Californians, though the magnitude of the threat can vary by year. Over 9,100 cases of pertussis were reported in California during 2010, the most in more than a half-century. After levels dropped in 2011 and 2012, they doubled in 2013 and continue to rise.

Young Infants at Highest Risk of Severe Pertussis

Infants younger than six months of age are most susceptible to hospitalization or death from pertussis. Infants can be protected by maternal antibodies that are transferred through the placenta. Early evidence suggests that maternal immunization with Tdap during the third trimester of pregnancy can prevent pertussis in young infants.

Optimal Timing of Maternal Tdap Administration

To maximize protection of young infants, the federal Advisory Committee on Immunization Practices (ACIP) recommends that all women should be administered Tdap during every pregnancy, preferably between 27 and 36 weeks' gestation. If Tdap is not administered during pregnancy, it should be given immediately postpartum. This will not provide direct protection to the infant, but may prevent transmission of pertussis from mother to infant.

Other Close Contacts

• Everyone who anticipates contact with an infant younger than 12 months of age should receive Tdap.
• Source: The Centers for Disease Control and Prevention.