# Tdap vaccination in pregnancy to protect the infant from whooping cough Intervention · id `maternal:maternal-tdap-vaccination` · Maternal & Newborn Atlas · release `c7fb95f1d15a7d13` (public) > General information from published sources, not medical advice, and not reviewed by clinicians. Check the cited source before relying on anything here. The atlas's own text and curation may be reused under Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0, https://creativecommons.org/licenses/by-nc/4.0/): credit the atlas, and do not use it commercially. See the atlas About page. Text quoted from a source stays under that source's own terms, given as the source's reuse\_basis. The atlas's reuse terms do not cover it. The downloads list each quotation with its source in third\_party\_quotations. Also called: Tdap Browse, life stage: Pregnancy; Infant follow-up Browse, care area: The baby's first year ## In plain language A Tdap vaccine (tetanus, diphtheria and whooping cough) given to a pregnant person so that her baby has some protection against whooping cough in the first months of life. A US study of babies younger than 2 months estimated that Tdap given in the third trimester of pregnancy was 77.7% effective against whooping cough in the baby. ## Technical summary The vaccine is given to the mother and the outcome is measured in the infant, so the claim uses an infant context and states the mother's exposure. The evidence is a US case-control evaluation (Clinical Infectious Diseases 2017) of infants younger than 2 months, read as a PubMed abstract only; observational design, so it estimates effectiveness without randomisation. MedlinePlus names Tdap as one of the two US whooping cough vaccines. The abstract says Tdap was recommended in 2012 for women during each pregnancy. ## Claims, with the population each applies to ## Context: Infants younger than 2 months in six US states, born to mothers who were or were not vaccinated with Tdap in pregnancy (case-control evaluation) Recipient: Newborn; Population: Infants younger than 2 months with pertussis (cases, cough onset 1 January 2011 to 31 December 2014) and hospital-matched controls chosen from birth certificates, from six US Emerging Infections Program states. Mothers counted as vaccinated if they received Tdap at least 14 days before delivery; the abstract reports 240 cases and 535 controls.; Care setting: Population-based case-control evaluation in six states with mother interviews and provider-verified immunisation records.; Geography: Six US Emerging Infections Program states (the abstract does not name them); Life stage: Infants younger than 2 months; Gestational age: Not reported; Postnatal age: Not reported; Follow-up: Not applicable (case-control design) ### A US case-control evaluation compared 240 infants younger than 2 months who had pertussis, with cough onset from 1 January 2011 to 31 December 2014 in six Emerging Infections Program states, with 535 hospital-matched controls. Mothers were counted as vaccinated during pregnancy if they received Tdap at least 14 days before delivery. In the third trimester, 17 case mothers (7.1%) and 90 control mothers (16.8%) had received Tdap. The multivariable vaccine effectiveness for Tdap given in the third trimester was 77.7% (95% confidence interval 48.3% to 90.4%), and 90.5% (95% confidence interval 65.2% to 97.4%) against cases that were hospitalised. - Category: Effect - Evidence stage: Observational - Certainty: Certainty not assessed - Applies to: Recipient: Newborn; Population: Infants younger than 2 months with pertussis (cases, cough onset 1 January 2011 to 31 December 2014) and hospital-matched controls chosen from birth certificates, from six US Emerging Infections Program states. Mothers counted as vaccinated if they received Tdap at least 14 days before delivery; the abstract reports 240 cases and 535 controls.; Care setting: Population-based case-control evaluation in six states with mother interviews and provider-verified immunisation records.; Geography: Six US Emerging Infections Program states (the abstract does not name them); Life stage: Infants younger than 2 months; Gestational age: Not reported; Postnatal age: Not reported; Follow-up: Not applicable (case-control design) - Limitations: Only the PubMed abstract was read; the full text was not. This is an observational case-control design in which effectiveness is estimated as (1 minus the odds ratio) times 100, so it cannot show cause the way a randomised trial can. The PMC copy is not in the Open Access subset and was not read. The authors conclude that vaccination during pregnancy is an effective way to protect infants in the early months of life. - Last checked: 2026-10-15 - Sources: 1. Supports: Impact of the US Maternal Tetanus, Diphtheria, and Acellular Pertussis Vaccination Program on Preventing Pertussis in Infants <2 Months of Age: A Case-Control Evaluation (Publication, edition PubMed record (abstract and bibliographic data) from NCBI E-utilities. The full text and the version of record were not fetched.) Locator: Abstract, METHODS, sentence 1, fragment 1 of 2. Retrieved 2026-10-15T13:48:54Z. Source state: Current. Snapshot hash: d2a5a5de3b3041bbc154d88ea9d170d3ed2c87d99d919173844b89e7410461c6. How it applies: PubMed abstract. 2. Supports: Impact of the US Maternal Tetanus, Diphtheria, and Acellular Pertussis Vaccination Program on Preventing Pertussis in Infants <2 Months of Age: A Case-Control Evaluation (Publication, edition PubMed record (abstract and bibliographic data) from NCBI E-utilities. The full text and the version of record were not fetched.) Locator: Abstract, METHODS, sentence 1, fragment 2 of 2. Retrieved 2026-10-15T13:48:54Z. Source state: Current. Snapshot hash: d2a5a5de3b3041bbc154d88ea9d170d3ed2c87d99d919173844b89e7410461c6. How it applies: PubMed abstract. 3. Supports: Impact of the US Maternal Tetanus, Diphtheria, and Acellular Pertussis Vaccination Program on Preventing Pertussis in Infants <2 Months of Age: A Case-Control Evaluation (Publication, edition PubMed record (abstract and bibliographic data) from NCBI E-utilities. The full text and the version of record were not fetched.) Locator: Abstract, METHODS, sentence 2. Retrieved 2026-10-15T13:48:54Z. Source state: Current. Snapshot hash: d2a5a5de3b3041bbc154d88ea9d170d3ed2c87d99d919173844b89e7410461c6. How it applies: PubMed abstract. 4. Supports: Impact of the US Maternal Tetanus, Diphtheria, and Acellular Pertussis Vaccination Program on Preventing Pertussis in Infants <2 Months of Age: A Case-Control Evaluation (Publication, edition PubMed record (abstract and bibliographic data) from NCBI E-utilities. The full text and the version of record were not fetched.) Locator: Abstract, METHODS, sentence 5, fragment 1 of 2. Retrieved 2026-10-15T13:48:54Z. Source state: Current. Snapshot hash: d2a5a5de3b3041bbc154d88ea9d170d3ed2c87d99d919173844b89e7410461c6. How it applies: PubMed abstract. 5. Supports: Impact of the US Maternal Tetanus, Diphtheria, and Acellular Pertussis Vaccination Program on Preventing Pertussis in Infants <2 Months of Age: A Case-Control Evaluation (Publication, edition PubMed record (abstract and bibliographic data) from NCBI E-utilities. The full text and the version of record were not fetched.) Locator: Abstract, METHODS, sentence 6. Retrieved 2026-10-15T13:48:54Z. Source state: Current. Snapshot hash: d2a5a5de3b3041bbc154d88ea9d170d3ed2c87d99d919173844b89e7410461c6. How it applies: PubMed abstract. 6. Supports: Impact of the US Maternal Tetanus, Diphtheria, and Acellular Pertussis Vaccination Program on Preventing Pertussis in Infants <2 Months of Age: A Case-Control Evaluation (Publication, edition PubMed record (abstract and bibliographic data) from NCBI E-utilities. The full text and the version of record were not fetched.) Locator: Abstract, RESULTS, sentence 1, fragment 1 of 2. Retrieved 2026-10-15T13:48:54Z. Source state: Current. Snapshot hash: d2a5a5de3b3041bbc154d88ea9d170d3ed2c87d99d919173844b89e7410461c6. How it applies: PubMed abstract. 7. Supports: Impact of the US Maternal Tetanus, Diphtheria, and Acellular Pertussis Vaccination Program on Preventing Pertussis in Infants <2 Months of Age: A Case-Control Evaluation (Publication, edition PubMed record (abstract and bibliographic data) from NCBI E-utilities. The full text and the version of record were not fetched.) Locator: Abstract, RESULTS, sentence 1, fragment 2 of 2. Retrieved 2026-10-15T13:48:54Z. Source state: Current. Snapshot hash: d2a5a5de3b3041bbc154d88ea9d170d3ed2c87d99d919173844b89e7410461c6. How it applies: PubMed abstract. 8. Supports: Impact of the US Maternal Tetanus, Diphtheria, and Acellular Pertussis Vaccination Program on Preventing Pertussis in Infants <2 Months of Age: A Case-Control Evaluation (Publication, edition PubMed record (abstract and bibliographic data) from NCBI E-utilities. The full text and the version of record were not fetched.) Locator: Abstract, RESULTS, sentence 2, fragment 1 of 2. Retrieved 2026-10-15T13:48:54Z. Source state: Current. Snapshot hash: d2a5a5de3b3041bbc154d88ea9d170d3ed2c87d99d919173844b89e7410461c6. How it applies: PubMed abstract. 9. Supports: Impact of the US Maternal Tetanus, Diphtheria, and Acellular Pertussis Vaccination Program on Preventing Pertussis in Infants <2 Months of Age: A Case-Control Evaluation (Publication, edition PubMed record (abstract and bibliographic data) from NCBI E-utilities. The full text and the version of record were not fetched.) Locator: Abstract, RESULTS, sentence 2, fragment 2 of 2. Retrieved 2026-10-15T13:48:54Z. Source state: Current. Snapshot hash: d2a5a5de3b3041bbc154d88ea9d170d3ed2c87d99d919173844b89e7410461c6. How it applies: PubMed abstract. 10. Background: Impact of the US Maternal Tetanus, Diphtheria, and Acellular Pertussis Vaccination Program on Preventing Pertussis in Infants <2 Months of Age: A Case-Control Evaluation (Publication, edition PubMed record (abstract and bibliographic data) from NCBI E-utilities. The full text and the version of record were not fetched.) Locator: Abstract, BACKGROUND, sentence 2, fragment 1 of 2. Retrieved 2026-10-15T13:48:54Z. Source state: Current. Snapshot hash: d2a5a5de3b3041bbc154d88ea9d170d3ed2c87d99d919173844b89e7410461c6. How it applies: PubMed abstract (context for the claim). 11. Background: Impact of the US Maternal Tetanus, Diphtheria, and Acellular Pertussis Vaccination Program on Preventing Pertussis in Infants <2 Months of Age: A Case-Control Evaluation (Publication, edition PubMed record (abstract and bibliographic data) from NCBI E-utilities. The full text and the version of record were not fetched.) Locator: Abstract, CONCLUSIONS, sentence 1. Retrieved 2026-10-15T13:48:54Z. Source state: Current. Snapshot hash: d2a5a5de3b3041bbc154d88ea9d170d3ed2c87d99d919173844b89e7410461c6. How it applies: PubMed abstract (context for the claim). ## Connected pages - Case-control evaluation: effectiveness against pertussis in infants younger than 2 months: Whooping cough (pertussis) in young infants (`maternal:infant-pertussis`) [a claim, not a settled fact; see claim `maternal:claim-maternal-tdap-ve-infants-under-2-months` and its context] - Filed under this front: Medicines and vaccines (`maternal:front-medicines-and-vaccines`) ## Provenance Content hash: 048c94191379e5f9f4ffca407778cf0f35bbd14b53090a59c46c78f12bae3217 Last substantive edit: 2026-10-15 Evidence last checked: 2026-10-15