IMPORTANCE: The Advisory Committee on Immunization Practices (ACIP) recommends the @entity116 , diphtheria, and acellular pertussis (Tdap) vaccine for pregnant @entity1 during each pregnancy, regardless of prior immunization status. However, safety data on repeated Tdap vaccination in pregnancy is lacking. OBJECTIVE: To determine whether receipt of Tdap vaccine during pregnancy administered in close intervals from prior @entity116 -containing vaccinations is associated with acute adverse events in mothers and adverse birth outcomes in neonates. DESIGN, SETTING, AND @entity1 : A retrospective cohort study in 29,155 pregnant @entity1 aged 14 through 49 years from January 1, 2007, through November 15, 2013, using data from 7 Vaccine Safety Datalink sites in California, Colorado, Minnesota, Oregon, Washington, and Wisconsin. EXPOSURES: @entity1 who received Tdap in pregnancy following a prior @entity116 -containing vaccine less than 2 years before, 2 to 5 years before, and more than 5 years before. MAIN OUTCOMES AND MEASURES: Acute adverse events (fever, @entity566 , and local reactions) and adverse birth outcomes (small for gestational age, @entity3152 , and low birth weight) were evaluated. @entity1 who were vaccinated with Tdap in pregnancy and had a prior @entity116 -containing vaccine more than 5 years before served as controls. RESULTS: There were no statistically significant differences in rates of medically attended acute adverse events or adverse birth outcomes related to timing since prior @entity116 -containing vaccination. [table: see text]. CONCLUSIONS AND RELEVANCE: Among @entity1 who received Tdap vaccination during pregnancy, there was no increased risk of acute adverse events or adverse birth outcomes for those who had been previously vaccinated less than 2 years before or 2 to 5 years before compared with those who had been vaccinated more than 5 years before. These findings suggest that relatively recent receipt of a prior @entity116 -containing vaccination does not increase risk after Tdap vaccination in pregnancy.

Association of Tdap Vaccination With Acute Events and Adverse Birth Outcomes Among Pregnant XXXX With Prior Tetanus-Containing Immunizations.

@entity1 :: ('9606', 'Species') :: ['women', 'Women', 'PARTICIPANTS'] @entity566 :: ('MESH:D006967', 'Disease') :: ['allergy'] @entity116 :: ('MESH:D013746', 'Disease') :: ['tetanus'] @entity3152 :: ('MESH:D007752', 'Disease') :: ['preterm delivery']
@entity1 :: (9606,Species) :: ['Women']
