Vaccines During Pregnancy
Vaccines given in pregnancy to protect the pregnant person and to pass antibodies to the baby before birth.
Last revised
Key takeaways
- Tdap (whooping cough): during every pregnancy, ideally between 27 and 36 weeks
- Flu shot: any trimester during flu season; the shot, not the nasal spray
- Most useful single change: Ask at a prenatal visit which vaccines you are due for and when.
- Commonest mistake: Skipping Tdap because you had it in a previous pregnancy; it is recommended every time.
- See a doctor if any of the signs under "When to get help" below apply to you.
Why it matters
Newborns are too young for some vaccines, so antibodies made during pregnancy are their main protection against whooping cough, flu and RSV in the first months of life.
The numbers, in one place
| Measure | Figure |
|---|---|
| Tdap (whooping cough) | during every pregnancy, ideally between 27 and 36 weeks |
| Flu shot | any trimester during flu season; the shot, not the nasal spray |
| RSV vaccine | at 32 to 36 weeks, given September through January in most of the US |
| COVID-19 vaccine | ask your clinician about the current recommendation |
| Not given during pregnancy | live vaccines such as MMR and chickenpox |
What helps
- Ask at a prenatal visit which vaccines you are due for and when
- Get your flu shot as soon as it is available in the fall if you are pregnant during flu season
- Ask family members and caregivers who will be around the baby to be up to date on their vaccines
- If you do not get the RSV vaccine in pregnancy, ask your baby's doctor about an RSV antibody shot for the baby
What to avoid
- Skipping Tdap because you had it in a previous pregnancy; it is recommended every time
- Getting live vaccines while pregnant
- Relying on social media for vaccine safety information instead of your clinician or pharmacist
In depth
Vaccines in pregnancy work on two levels. They protect the pregnant person, who is more likely to become seriously ill from infections such as flu and COVID-19 because pregnancy changes the immune system, heart and lungs. And they protect the baby, because antibodies made in response to the vaccine are actively carried across the placenta, especially in the third trimester.
This transfer is why timing matters. Tdap is recommended in the third trimester, when antibody levels in the parent are high and transport across the placenta is greatest, so that the newborn is born with a supply. These borrowed antibodies fade over the first months of life, bridging the gap until the baby can start building protection from their own vaccines.
Vaccines given in pregnancy are inactivated or made from pieces of a germ, so they cannot cause the infection they protect against. Live vaccines, such as MMR and chickenpox, are not given during pregnancy as a precaution; if you are not immune, they are usually offered after birth. Planning vaccines before pregnancy is the ideal way to cover those.
Signs and symptoms
- A sore, red or swollen arm where the shot was given
- Tiredness, headache or muscle aches for a day or two
- A low-grade fever, which can be treated with acetaminophen (Tylenol)
- Signs of a rare allergic reaction, such as hives, swelling of the face or trouble breathing, usually within minutes to hours
Causes and risk factors
- Changes in immunity, heart and lung function in pregnancy that make some infections more severe
- Newborns being too young to receive some vaccines
- Seasonal timing of flu and RSV, which determines when shots are offered
- Missing records or uncertainty about past vaccines and immunity
- Misinformation that leads to delays or skipped vaccines
How it is checked
There is no test needed before most pregnancy vaccines. Your provider will review your vaccine record, your due date and the season, and recommend the shots you need. Early in pregnancy, blood tests often check immunity to rubella and, in some cases, to chickenpox and hepatitis B, which helps plan vaccines after birth.
If you are unsure what you have had, your state immunization information system may have a record that your provider or pharmacist can look up. Missing records are not a reason to delay recommended pregnancy vaccines.
Related topics
- What the Guidance Really Says About Vaccination in Pregnancy (Vaccinations)
- The Evidence on Vaccination in Older Adults, Without the Hype (Healthy Aging)
- RSV (Respiratory Syncytial Virus): Sorting the Evidence From the Noise (Infectious Diseases)
- Childhood Vaccinations: Sorting the Evidence From the Noise (Children's Health)
Where to go next
- Vaccines During Pregnancy, Explained Without the Jargon
- Vaccines During Pregnancy: The Practical To-Do List
- Pregnancy and Postpartum: The Complete Guide
- Postpartum Depression: What Published Guidance Supports
- The Evidence on Breastfeeding Basics, Without the Hype
When to get help
Call your provider for a fever of 100.4°F (38°C) or higher or symptoms that worry you after a vaccine. Call 911 for signs of a severe allergic reaction, such as swelling of the face or throat, trouble breathing or a fast heartbeat with dizziness.
Where this comes from
- CDC — Pregnancy and Vaccination
- American College of Obstetricians and Gynecologists — Maternal Immunization
How this page was put together
Every figure, recommendation and warning above is taken from the guidance named in Where this comes from. Nothing on this page is inferred, summarized or generalized beyond what those bodies publish: where they give a number, it is their number, and where they are silent, so are we. Pages are rebuilt whenever the underlying record changes. Sign-off by a named clinician, where it has happened, is shown at the top of the page along with the date.
Medical disclaimer
This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to your doctor, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 911.