Tdap Vaccine Appears Safe for Moms-to-Be

Tdap vaccination during pregnancy not linked to adverse outcomes among women with prior tetanus immunization

/ Author:  / Reviewed by: Jennifer Gershman, PharmD, CPh

(RxWiki News) The safety of whooping cough vaccination during pregnancy can be a big concern for expecting moms and their doctors. But a new finding may help put that fear to rest.

A new study from the Centers for Disease Control and Prevention (CDC) found no increased risk of adverse health events or adverse birth outcomes among women who received the tetanus, diphtheria and acellular pertussis (Tdap) vaccine during pregnancy — regardless of tetanus-containing immunization in the five years prior.

"Our findings should reassure patients and clinicians who might be hesitant to give [the] Tdap vaccine to pregnant women who recently received a Tdap or other tetanus-containing vaccination," wrote lead study author Lakshmi Sukumaran, MD, MPH, a CDC pediatric infectious disease specialist, and colleagues.

Tetanus is a serious bacterial infection that affects the central nervous system, leading to painful muscle contractions, particularly in the jaw and neck muscles. In some cases, it can be deadly. Diphtheria is another serious bacterial infection that typically affects the mucous membranes of the nose and throat. This disease can lead to breathing problems, heart failure and paralysis.

Pertussis, also known as whooping cough, is a highly contagious bacterial infection marked by intense coughing fits.

The Tdap vaccine can protect adults and teens from these diseases. Babies and young children, however, can still be at risk of infection. This is because their first vaccines do not begin until 2 months of age and are not boosted until age 11 or 12.

Because infants are at a high risk for severe, life-threatening complications from pertussis, the US Advisory Committee on Immunization Practices (ACIP) recommends the Tdap for all pregnant women between the 27th and 36th week, regardless of prior immunization status.

However, according to these researchers, safety data on repeated Tdap vaccination in pregnancy was lacking.

For this study, Dr. Sukumaran and team used data from Vaccine Safety Datalink sites across the US to look at 29,155 pregnant women ages 14 to 49.

All of these woman had received a Tdap during pregnancy following a prior tetanus-containing vaccine less than two years before, between two and five years before or more than five years before the Tdap.

No significant differences in the rates of adverse health events in the mothers, such as fever, allergy or local reactions, were found among the three groups.

No significant differences in the rates of adverse birth outcomes, such as preterm delivery or low birth weight, were found.

According to Dr. Sukumaran and team, more research is needed to determine whether there are differences in other important adverse birth outcomes when Tdap is given during pregnancy following a prior tetanus-containing vaccine.

This study was published Oct. 20 in the journal JAMA.

The CDC and the National Institute of Allergy and Infectious Diseases funded this research. Several authors disclosed potential conflicts of interest.

Review Date: 
October 20, 2015
Last Updated:
October 22, 2015