FPIN's Help Desk Answers
Maternal Pertussis Vaccination During Pregnancy
Am Fam Physician. 2019 Apr 1;99(7):454-455.
How effective is prenatal maternal administration of the tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine in preventing pertussis in infants?
Women should receive the Tdap vaccine during pregnancy regardless of previous immunization history. Infants whose mothers received prenatal immunization had 50% fewer cases of pertussis compared with those whose mothers received postpartum immunization. (Strength of Recommendation: B, based on cohort and case-control studies.) Prenatal maternal Tdap vaccination is 91% effective in preventing pertussis during the first three months of life and 93% effective in preventing pertussis in the first eight weeks.
A 2017 cohort study reviewed records of California mothers 14 to 44 years of age who received the Tdap vaccine during pregnancy or up to 14 days after delivery to determine which infants were at lower risk of pertussis during the first eight weeks of life.1 Infants born before 27 weeks' gestation and with birth weights less than 500 g were excluded. Of the 74,504 women included in the study, 58% were vaccinated during pregnancy, and 42% were vaccinated postpartum. Of those vaccinated during pregnancy, 77% received the Tdap vaccine at 27 to 36 weeks' gestation; the remaining 23% received the vaccine after 36 weeks' gestation. Of the infants born to mothers who were vaccinated during pregnancy, 0.02% contracted pertussis in the first eight weeks of life compared with 0.05% of those whose mothers were vaccinated postpartum (number needed to treat = 3,333; P = .01). The incidences of pertussis in infants younger than 12 weeks were 0.03% and 0.08%, respectively (number needed to treat = 2,000; P = .01). The incidences of pertussis in the first year of life were similar between groups: 0.14% for infants of mothers vaccinated prenatally and 0.19% for infants of mothers vaccinated postpartum (P = .11).
A 2016 British cohort study evaluated the effectiveness
1. Winter K, Nickell S, Powell M, Harriman K. Effectiveness of prenatal versus postpartum tetanus, diphtheria, and acellular pertussis vaccination in preventing infant pertussis. Clin Infect Dis. 2017;64(1):3–8.
2. Amirthalingam G, Campbell H, Ribeiro S, et al. Sustained effectiveness of the maternal pertussis immunization program in England 3 years following introduction. Clin Infect Dis. 2016;63(suppl 4):S236–S243.
3. Dabrera G, Amirthalingam G, Andrews N, et al. A case-control study to estimate the effectiveness of maternal pertussis vaccination in protecting newborn infants in England and Wales, 2012–2013. Clin Infect Dis. 2015;60(3):333–337.
Help Desk Answers provides answers to questions submitted by practicing family physicians to the Family Physicians Inquiries Network (FPIN). Members of the network select questions based on their relevance to family medicine. Answers are drawn from an approved set of evidence-based resources and undergo peer review. The strength of recommendations and the level of evidence for individual studies are rated using criteria developed by the Evidence-Based Medicine Working Group (http://www.cebm.net).
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