Tdap needed with each pregnancy, says CDC advisory committee

On October 24, 2012, the Advisory Committee on Immunization Practices (ACIP) of the CDC voted to recommend administering the tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap) to pregnant women with every pregnancy, regardless of the women’s previous Tdap history.

The ACIP now recommends that providers of prenatal care implement a Tdap immunization program for all pregnant women. To maximize the maternal antibody response and passive antibody transfer to the infant, optimal timing for Tdap administration is between 27 weeks’ and 36 weeks’ gestation, according to the ACIP. For women not previously vaccinated with Tdap, the ACIP recommends administering Tdap immediately postpartum if it is not administered during pregnancy.

In related news, a New England Journal of Medicine letter published on February 7, 2013, noted the first appearance in the United States of pertussis strains that are missing pertactin, a protein that helps pertussis bacteria attach to the lining of the airways. The CDC notes that although pertactin is an important part of pertussis vaccines, “pertussis vaccines remain effective against the pertactin-negative pertussis strains since other components of the vaccines provide protection.”

It is most likely that the change in pertussis vaccines from whole cell to acellular in the 1990s, along with better diagnostics and increased reporting, are driving the resurgence of pertussis throughout the United States, claims the CDC.

According to the CDC, during 2012 increased numbers of pertussis cases or outbreaks were reported in a majority of states. As of January 10, 2013, 49 states and Washington, DC reported increases in the disease in 2012 compared with 2011.

Centers for Disease Control and Prevention. ACIP provisional updated recommendations on use of tetanus toxoid, reduced diphtheria toxoid and acellular pertussis vaccine (Tdap) for pregnant women. www.cdc.gov/vaccines/recs/provisional/downloads/Tdap-pregnant-Oct-2012.pdf. Accessed February 19, 2013.

Centers for Disease Control and Prevention. Pertussis (whooping cough): Pertactin-negative pertussis strains. www.cdc.gov/pertussis/pertactin-neg-strain.html. Accessed February 19, 2013.

Centers for Disease Control and Prevention. Pertussis (whooping cough): Outbreaks. www.cdc.gov/pertussis/outbreaks.html. Accessed February 19, 2013.