Tdap Vaccine During Pregnancy
- Alex Kelly
- Nov 18, 2024
- 3 min read
What is the Tdap Vaccine?
The Tdap vaccine protects against tetanus, diphtheria, and pertussis (whooping cough). It is most commonly recommended to pregnant women in order to provide protection to baby, specifically from pertussis. There are two Tdap vaccines for pregnant women: Boostrix by GlaxoSmithKline and Adacel by Sanofi Pasteur.
What is Pertussis?
Pertussis is most commonly known as whooping cough. It is caused by a bacterium that infects the upper lungs, causing severe irritation and damage to the lining of the upper lungs and throat.
Symptoms start off the same as a common cold, and then worsen into a prolonged cough so severe a person can barely breathe, and when breaths are possible they sound like a gasping "whoop" (usually not present in infants less than one).
It is transmitted like the common cold and can last as long as three months, even with treatment.
Fortunately, most cases are mild. A moderate case can involve coughing spells that can cause infants or young children to turn blue. Severe cases require ICU care - requiring oxygen, IV fluids, and suctioning of secretions. Infants and the elderly have the highest risk.
Pertussis Stats 2014-2022
According to the CDC, there are an estimated 24.1 million cases of whooping cough and about 160,700 deaths in children younger than age 5 years WORLDWIDE annually (out of ~8 billion).
Since 2010, the CDC has reported between 10,000-50,000 whooping coughing cases in the UNITED STATES annually. About 1/2 of babies younger than 1 need hospital care, and in rare cases it can be deadly. Up to 20 babies have died each year since 2010 in the US.
the above are CASES (not deaths) per year in the United States. keep in mind while there is typically a rise and fall pattern every 5 years, the drastically lower numbers 2020-2021 most likely had to do with COVID quarantine. https://www.cdc.gov/pertussis/php/surveillance/pertussis-incidence-by-age-group-and-year.html
2023 Provisional Pertussis Stats
Vaccination Status:
6-11mo: 102 vaccinated, 46 partially vaccinated, 13 unvaccinated, 192 unknown
1-4yr: 484 vaccinated, 114 partially vaccinated, 41 unvaccinated, 625 unknown
5-6yr: 288 vaccinated, 32 partially vaccinated, 20 unvaccinated, 159 unknown
Why Some Decline Tdap
There have only been a handful of safety studies. Two of the studies that were conducted with an ethics review and approved by the IRB, and received Sanofi’s support, deemed the vaccine safe for pregnancy. However one included only 48 women and the other only 273 (1,2). For some, the study numbers are not large enough to feel comfortable with the results.
The Tdap vaccines contains 0.33-0.39 mg (3) of aluminum. Based on FDA guidelines, the max amount of aluminum exposure for infants via parenteral nutrition is 0.025 mg/L (4) - the amount in the Tdap vaccine exceeds this, and while a different category and means, still makes many parents uncomfortable.
If a prenatal or postnatal issue were to arise for mom or baby, without a known underlying cause, many parents wish to not have vaccines on the table as a possible cause - especially since injuries and issues related to vaccines are very hard to prove.
If a baby is going to be breast-fed and stay at home vs going to daycare from an early age, then the risk of pertussis is extremely low, and mom may feel comfortable skipping the vaccine for herself.
Why Some Choose Tdap
Pertussis is a common disease and most serious in the first 6 months of life. There is typically a rise and fall pattern of Pertussis every 5 years.
A larger study of almost 150,000 infants over the span of 5 years showed a 91% effectiveness rate for the first 2 months, and 69% for the first year (5). Many parents find comfort in those percentages, and want to provide protection for their infant in that manner. However, it’s important to note that this study tested effectiveness, not safety.
Many parents would rather choose the risk of the vaccine than the risk of the disease, especially if their baby is going to be in daycare before they are able to receive the first dose of DTaP.
Sources:
1 Munoz FM, Bond NH, Maccato M, et al. Safety and Immunogenicity of Tetanus Diphtheria and Acellular Pertussis (Tdap) Immunization During Pregnancy in Mothers and Infants: A Randomized Clinical Trial. JAMA. 2014;311(17):1760–1769. doi:10.1001/jama.2014.3633
2 Scott A Halperin, Joanne M Langley, Lingyun Ye, Donna MacKinnon-Cameron, May Elsherif, Victoria M Allen, Bruce Smith, Beth A Halperin, Shelly A McNeil, Otto G Vanderkooi, Shannon Dwinnell, R Douglas Wilson, Bruce Tapiero, Marc Boucher, Nicole Le Saux, Andrée Gruslin, Wendy Vaudry, Sue Chandra, Simon Dobson, Deborah Money, A Randomized Controlled Trial of the Safety and Immunogenicity of Tetanus, Diphtheria, and Acellular Pertussis Vaccine Immunization During Pregnancy and Subsequent Infant Immune Response, Clinical Infectious Diseases, Volume 67, Issue 7, 1 October 2018, Pages 1063–1071, https://doi.org/10.1093/cid/ciy244
4 https://www.fda.gov/drugs/drug-safety-and-availability/infants-risk-aluminum-toxicity-unapproved-potassium-phosphates-drug-product#:~:text=FDA's%20guidance%20includes%20a%20recommendation,5%20mcg%2Fkg%2Fday.
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