Vaccine Safety

The tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine is safe, for both mother and infant, to administer any time during pregnancy. Since the maternal immune response to the vaccine 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, pain, and tenderness at the injection site
Body-ache
Fatigue
Fever

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 Tdap vaccine 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.

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Breastfeeding Safety after Tdap Vaccination

Breastfeeding is not a contraindication for receiving Tdap vaccine and is, in fact, fully compatible with Tdap vaccination. You can and should give Tdap vaccine during pregnancy to women who plan to breastfeed.

Coadministration of Pertussis and Flu Vaccines

You can safely administer pertussis and flu vaccines to pregnant women at the same visit. Pregnant women should receive the flu vaccine by the end of October, if possible. You can administer the flu vaccine during any trimester. CDC recommends you administer the pertussis vaccine 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.