We know that pregnant women are supposed to get a Tdap vaccine.
Although recommendations on exactly when to get it have changed over the years, it has been a universal recommendation for pregnant women since at least 2011.
But why?
Mother’s Tdap Shot Protects Her Newborn Baby
It’s about passive immunity.
“Tdap given to pregnant women will stimulate the development of maternal antipertussis antibodies, which will pass through the placenta, likely providing the newborn with protection against pertussis in early life, and will protect the mother from pertussis around the time of delivery, making her less likely to become infected and transmit pertussis to her infant.”
Updated Recommendations for Use of Tetanus Toxoid, Reduced Diphtheria Toxoid, and Acellular Pertussis Vaccine (Tdap) in Pregnant Women — Advisory Committee on Immunization Practices (ACIP), 2012
A dose of Tdap in the third trimester helps ensure that both mother and baby have as much protection against pertussis as possible, as those newly formed antibodies pass to them through the placenta.
“To maximize the maternal antibody response and passive antibody transfer to the infant, optimal timing for Tdap administration is between 27 and 36 weeks gestation although Tdap may be given at any time during pregnancy.”
Updated Recommendations for Use of Tetanus Toxoid, Reduced Diphtheria Toxoid, and Acellular Pertussis Vaccine (Tdap) in Pregnant Women — Advisory Committee on Immunization Practices (ACIP), 2012
But do you really have to wait until the third trimester?
“The mother-to-fetus transfer of IgG may begin as early as 13 weeks of gestation; however, the largest amount of anti-bodies is transferred in the third trimester.”
Plotkin’s Vaccines 7th Edition
You can give the dose earlier if really necessary, but the third trimester is ideal, as it provides maximum protection for the mother around the time of delivery and ensures that the baby gets as many antibodies as possible.
But doesn’t passive immunity from a mother’s previous vaccine doses provide protection to her new baby?
In many cases, yes.
As long as a mother has immunity to a disease, whether from a vaccine or natural infection, she will pass on temporary immunity to that disease to her baby. We see this type of passive immunity for many diseases, including measles, chicken pox, etc.
Unfortunately, waning immunity from pertussis vaccines means that pregnant mothers need a Tdap vaccine with each and every pregnancy to get those antibody levels high enough to protect her baby.
Pertussis is a life-threatening disease for newborns and young infants.
Tdap is a safe vaccine, with few risks.
“Fewer babies will be hospitalized for and die from pertussis when Tdap is given during pregnancy rather than during the postpartum period.”
5 Facts about Tdap and Pregnancy
Get vaccinated and protect yourself and your baby when you are pregnant.
More on Tdap in Pregnancy
- How Does a Mother’s Flu Shot Protect a Newborn Baby?
- Influenza and Tdap Vaccination Rates Among Pregnant Women
- Why is the Tdap Vaccine in Category C?
- Is Measles Dangerous If You Are Pregnant?
- What Shots Do You Need to Be Around a Newborn?
- What to Do If Your Child Is Exposed to Pertussis
- Myths About Your Baby’s Immature Immune System
- Grave Reminders of Life Before Vaccines
- Strategies for Increasing Childhood Vaccination Rates
- CDC – 5 Facts about Tdap and Pregnancy
- IAC – Ask the Experts about Tdap and Pregnancy
- IAC – Standing Orders for Administering Tdap to Pregnant Women
- Flu Shots During Pregnancy Lead to Healthier Mothers and Babies
- Pertussis Vaccination in Every Pregnancy is Safe and Effective
- Prenatal Tdap Workgroup Resources
- What vaccinations are recommended during pregnancy?
- MMWR – Updated Recommendations for Use of Tetanus Toxoid, Reduced Diphtheria Toxoid, and Acellular Pertussis Vaccine (Tdap) in Pregnant Women — Advisory Committee on Immunization Practices (ACIP), 2012
- Plotkin’s Vaccines 7th Edition
- The Sounds of Pertussis Family Stories
- Light for Riley
- Whooping cough: Alice turned her daughter’s brush with death into a positive campaign for better health
- As Whooping Cough Rebounds in U.S., Infants at Greatest Risk
- The Death of Colin, Pamela and Kevin Durkin’s Infant Son
- Whooping cough dangers persist
- Travis County baby is state’s first pertussis death this year
- Brady’s Battle with Pertussis
- Surge in whooping cough: A mother’s heartbreaking loss
- Whooping cough remains a threat, despite vaccine, doctors say