Vaccine Safety
The tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine is safe, for both mother and baby, to administer any time during pregnancy. Since the maternal immune response to Tdap peaks about 2 weeks after administration, CDC recommends Tdap during the early part of gestational weeks 27 through 36 in order to maximize passive antibody transfer and protection at birth, not for any safety concerns.
Tdap vaccine safety for mother and infant
Both CDC and the Food and Drug Administration monitor vaccine safety through the Vaccine Adverse Event Reporting System (VAERS), a national vaccine safety surveillance program. Published studies that include VAERS data support the safe use of Tdap during pregnancy. To date, VAERS has not found any safety signals among pregnant women or their babies after Tdap vaccination. Administering the vaccine during pregnancy does not put your patients at increased risk for pregnancy complications like low birth weight or preterm delivery.
Pregnant women have been getting both tetanus and diphtheria toxoids (Td) and tetanus toxoid (TT) vaccines worldwide since the 1960s to prevent neonatal tetanus. Td and TT vaccines administered during pregnancy have not been shown to harm either the mother or baby/fetus.
See the Pregnancy and Whooping Cough Research page for a list of published articles specific to preventing pertussis in infants, including safety studies.
Common side effects from Tdap vaccination, including during pregnancy
Most side effects from Tdap vaccination, including vaccination during pregnancy, are mild or moderate, and self-resolving. The most common side effects include
- Erythema, swelling, and pain at the injection site
- Fatigue
- Fever
- Headache
- Vomiting, diarrhea, or stomachache
Severe side effects are extremely rare, especially in adults.
Risk of severe side effects from multiple Tdap doses
CDC and the American College of Obstetricians and Gynecologists (ACOG) consider the benefits of Tdap vaccination in multiple pregnancies to outweigh the theoretical risk for severe hypersensitivity due to administering the tetanus component of the Tdap vaccine more often (see ACOG’s Committee Opinion). Studies found that adults who receive 2 tetanus shots in a short period of time (within 2 years) were no more likely than adults getting their first dose of Tdap to have severe side effects. Manufacturers now make these vaccines with lower doses of the tetanus component than tetanus vaccines in the past. Researchers believe this change likely reduced the risk of severe local reactions.
Breastfeeding safety after Tdap vaccination
Breastfeeding is not a contraindication for receiving Tdap and is, in fact, fully compatible with Tdap vaccination. You can and should give Tdap during pregnancy to women who plan to breastfeed.
Coadministration of Tdap and flu vaccines
You can safely administer Tdap and flu vaccine to pregnant women at the same visit. September and October are generally good times to administer flu vaccine to pregnant women. You can administer the flu vaccine during any trimester. CDC recommends you administer Tdap during the early part of gestational weeks 27 through 36 in order to maximize passive antibody transfer to the infant.
Pertussis vaccines do not contain live bacteria
None of the pertussis vaccines (Tdap and DTaP) currently used in the United States contains any live bacteria.
Pertussis vaccines do not contain thimerosal
None of the pertussis vaccines (Tdap and DTaP) currently used in the United States contains thimerosal.
