Vaccines During Pregnancy: What Is Recommended and Why It Matters

Why does vaccination during pregnancy matter?

When you receive a vaccine during pregnancy, your immune system produces antibodies that cross the placenta and reach your baby before birth. This gives the newborn a head start of protection during the first weeks and months of life — a period when some infections are especially dangerous and babies are too young for their own vaccine series.

The vaccines recommended in pregnancy are specifically chosen because they use killed (inactivated) or protein-based ingredients, not live viruses, making them appropriate to give during pregnancy 1Ref 1Issa AN, Wodi AP, Moser CA, Cineas S (2025).Advisory Committee on Immunization Practices Recommended Immunization Schedule for Children and Adolescents Aged 18 Years or Younger — United States, 2025.Inactivated vaccines are safe in pregnancy; Tdap timing and maternal vaccination rationale.

Tdap: why it is given in every pregnancy

Whooping cough (pertussis) can be life-threatening in newborns, who cannot start their own DTaP vaccine series until two months of age. Giving Tdap to the pregnant person — ideally between 27 and 36 weeks — causes a surge of antibodies that transfer to the baby before birth 1Ref 1Issa AN, Wodi AP, Moser CA, Cineas S (2025).Advisory Committee on Immunization Practices Recommended Immunization Schedule for Children and Adolescents Aged 18 Years or Younger — United States, 2025.Inactivated vaccines are safe in pregnancy; Tdap timing and maternal vaccination rationale.

This is recommended during every pregnancy, even if you received Tdap before, because antibody levels decline over time and the goal is maximal antibody transfer to the baby. Earlier in the 27-to-36-week window generally produces higher antibody transfer than a later dose.

The 2025 ACIP adult immunization schedule confirms this recommendation applies in each pregnancy 2Ref 2Wodi AP, Issa AN, Moser CA, Cineas S (2025).Advisory Committee on Immunization Practices Recommended Immunization Schedule for Adults Aged 19 Years or Older — United States, 2025.Tdap recommended in every pregnancy per current ACIP adult schedule.

Flu shot: important for you and your baby

Pregnancy changes how the immune system and lungs work, which makes flu infections more likely to become severe. The inactivated flu shot (injectable form) is safe at any stage of pregnancy and is recommended any time during flu season 3Ref 3Centers for Disease Control and Prevention (2024).Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices — United States, 2024–25 Influenza Season.Inactivated influenza vaccine recommended at any stage of pregnancy; nasal spray contraindicated.

Antibodies from the flu shot also cross the placenta, offering some protection to the baby before and shortly after birth, since infants cannot receive their own flu vaccine until six months of age.

The live attenuated flu vaccine (nasal spray) is not recommended during pregnancy — only the injectable shot.

RSV vaccine: a newer option in the third trimester

RSV (respiratory syncytial virus) is among the most common causes of serious respiratory illness in infants in the first year of life. A maternal RSV vaccine — given once between 32 and 36 weeks of pregnancy — can transfer antibodies to the baby and reduce the risk of severe RSV illness in the first six months of life.

This is a relatively recent addition to prenatal vaccination guidance 4Ref 4Melgar M, Britton A, Roper LE, Talbot HK, Long SS, Kotton CN, Havers FP (2023).Use of Respiratory Syncytial Virus Vaccines in Older Adults: Recommendations of the Advisory Committee on Immunization Practices — United States, 2023.RSV vaccine background; maternal RSV vaccination context. Discuss it with your OB or midwife to understand whether it applies to your situation and whether it is available, as timing and local availability can vary.

Which vaccines should be avoided during pregnancy?

Vaccines made with live, weakened viruses are generally avoided during pregnancy because of a theoretical risk to the developing baby. These include:

• MMR (measles, mumps, rubella)
• Varicella (chickenpox)
• Live attenuated flu vaccine (nasal spray)

If you are not immune to rubella or varicella — something your prenatal bloodwork typically checks — these are usually given right after delivery before you leave the hospital.

Your provider will review your full vaccine history and determine if any catch-up vaccines make more sense postpartum rather than during pregnancy.

When should I discuss vaccines with my care team?

Your OB, midwife, or primary care provider should review your vaccine history at your first prenatal visit. They can identify which vaccines you are due for, flag anything that should wait until after delivery, and order any needed catch-up shots at the right time.

If you are in a high-risk group — for example, you work in healthcare, travel internationally, or have a chronic health condition — additional vaccines (hepatitis A, hepatitis B, pneumococcal) may also be discussed. People in your household who are not up to date on their own vaccinations may also be asked to catch up, since protecting a newborn often requires protecting those closest to them.