Medical Information
The information on this page is for educational and informational purposes only. It is not medical advice and should not be used to diagnose or treat any medical condition. Always consult your healthcare provider (doctor, midwife, or nurse) before making any decisions about your pregnancy or your baby's health.
health-safetyVaccines During Pregnancy: Which Are Safe, Which to Avoid, and When to Have Them
Which vaccines are recommended in pregnancy, which to avoid, and why vaccination protects both mother and newborn. NHS and CDC guidance explained clearly.
Fact-Checked & Transparent: This article is fact-checked against current CDC, WHO, ACOG, and NHS guidelines. All health information is based on authoritative medical sources. Last verified: June 2026.
⚠️ MEDICAL DISCLAIMER
This article is educational information only. It is NOT a substitute for professional medical advice, diagnosis, or treatment.
Always consult your pediatrician or healthcare provider before making any medical decisions for your baby or child. Every baby is unique, and professional medical guidance is essential.
In case of emergency, call 911 or your local emergency number.
Why Vaccination Matters During Pregnancy
Pregnancy alters the immune system in complex ways. To prevent the body from rejecting the fetus, immune responses are partially downregulated — which means certain infections hit harder during pregnancy than they would otherwise. Influenza, for example, is significantly more likely to cause serious complications including pneumonia and hospitalisation when contracted during pregnancy. Whooping cough (pertussis) can be fatal in newborns who are too young to be vaccinated themselves.
Vaccines during pregnancy work in two ways. First, they protect the pregnant woman directly. Second — and critically — the antibodies generated in response to the vaccine cross the placenta and provide the newborn baby with passive immunity in the first weeks of life, before the baby's own vaccination schedule can begin. This window of protection is particularly important for infections like pertussis and RSV, which can cause life-threatening illness in very young infants.
The World Health Organization (WHO), the NHS, and the US Centers for Disease Control and Prevention (CDC) all recommend specific vaccines during pregnancy. The guidance is based on extensive safety data and benefit-risk analysis.
Vaccines Recommended During Pregnancy in the UK
Whooping Cough (Pertussis) Vaccine
The NHS recommends the pertussis vaccine for every pregnant woman, ideally between 16 and 32 weeks of pregnancy. It is offered as part of a combination vaccine also covering diphtheria, tetanus, and polio (Tdap in the US; Boostrix IPV in the UK).
Whooping cough spreads very easily between people and can be deadly in babies under 6 months. Newborns are not protected by their own vaccination until they have received multiple doses. The antibodies passed from a vaccinated mother provide a bridge of protection during this vulnerable early period. NHS data consistently shows that maternal vaccination substantially reduces the risk of whooping cough in newborns.
If you did not have the vaccine during the recommended window and are now past 32 weeks, it can still be given up to 38 weeks. Speak to your midwife or GP if you are unsure whether you have received it in this pregnancy.
Flu (Influenza) Vaccine
The NHS offers a free flu vaccination to all pregnant women, regardless of gestational age. The vaccine changes each year to match the circulating strains, so previous flu vaccines do not provide ongoing protection.
Flu during pregnancy carries a higher risk of complications including pneumonia, premature labour, and hospital admission. The flu vaccine given in pregnancy is an inactivated vaccine (not a live vaccine), meaning it contains killed viral particles and cannot cause flu. It is safe at any stage of pregnancy, including the first trimester.
The CDC in the United States recommends the same: flu vaccination is strongly advised for all pregnant people, at any point during pregnancy, during flu season. This is one of the vaccines where delay is most potentially harmful — if flu season is underway, vaccination should not be deferred.
COVID-19 Vaccine
Both the NHS and the CDC recommend COVID-19 vaccination for pregnant women. Pregnancy increases the risk of serious illness from COVID-19, including preterm birth and admission to intensive care. Safety monitoring programmes in the UK and US covering tens of thousands of pregnant women have not identified concerns about vaccine safety for the mother or baby.
The mRNA vaccines (Pfizer-BioNTech and Moderna) are recommended for use in pregnancy by NHS and CDC guidance. The vaccine does not contain live virus and cannot infect the developing baby.
Booster doses are recommended when due during pregnancy. Speak to your GP or midwife if you have not yet received a primary course or a booster and are currently pregnant.
RSV Vaccine
Since autumn 2024, the NHS has offered an RSV (respiratory syncytial virus) vaccine to pregnant women from 28 weeks of pregnancy as part of a national programme. RSV is the most common cause of bronchiolitis in infants — a serious lower respiratory infection that hospitalises large numbers of babies each winter.
The vaccine (Abrysvo) is given as a single injection and works by building antibodies in the mother that pass to the baby before birth. Early data from the clinical trials showed significant reduction in severe RSV illness in infants in the months after birth.
In the United States, the FDA approved Abrysvo for use in pregnant women at 32 to 36 weeks gestation, and the CDC recommends it during this window.
Vaccines to Avoid During Pregnancy
The category of vaccines that must be avoided in pregnancy are live attenuated vaccines — vaccines that contain a weakened but live form of a virus or bacterium. Because the virus in these vaccines can replicate, there is a theoretical (and in some cases documented) risk of the vaccine strain causing infection in the fetus.
MMR (Measles, Mumps, Rubella)
The MMR vaccine is a live vaccine and is contraindicated during pregnancy. Women who are not immune to rubella (German measles) should receive the MMR vaccine at least one month before trying to conceive, or immediately after giving birth.
Rubella infection during pregnancy — particularly in the first trimester — can cause congenital rubella syndrome, a serious condition affecting the baby's heart, eyes, hearing, and brain. Checking rubella immunity is part of routine antenatal blood screening in the UK.
Chickenpox (Varicella) Vaccine
The chickenpox vaccine is also a live vaccine and is not given during pregnancy. Women who are not immune to chickenpox and who contract the infection during pregnancy face an elevated risk of serious complications including varicella pneumonia. If a non-immune pregnant woman is exposed to chickenpox, varicella zoster immunoglobulin (VZIG) can be given as a passive protection measure — this is not a vaccine but provides temporary antibodies. Speak to your GP or midwife immediately if you have been exposed.
Yellow Fever Vaccine
The yellow fever vaccine is a live vaccine normally avoided in pregnancy unless travel to a high-risk area is unavoidable. In that case, the risk of yellow fever infection must be weighed against the theoretical vaccine risk — a discussion that should take place with a GP or travel medicine specialist.
What If You Had a Live Vaccine Before Knowing You Were Pregnant?
This is a common concern. Many women receive a routine MMR or varicella vaccine without yet knowing they are pregnant. The reassuring evidence is that no cases of congenital rubella syndrome or vaccine-related harm have been documented in babies born to women who were inadvertently vaccinated with MMR in early pregnancy. The CDC and NHS both confirm that inadvertent vaccination is not a reason to consider ending a pregnancy. Do inform your midwife so the pregnancy can be monitored appropriately.
Addressing the Misconception That Vaccines Are Unsafe in Pregnancy
Concerns about vaccine safety in pregnancy are understandable but not supported by the evidence. The WHO states clearly that inactivated vaccines (such as flu, pertussis, COVID-19 mRNA vaccines, and RSV vaccines) are safe during pregnancy and have been assessed across large populations of pregnant women.
Studies involving millions of doses in pregnant women have not identified patterns of harm to the fetus, increased miscarriage risk, or adverse birth outcomes attributable to recommended vaccines. The NHS advises that the risks of not vaccinating — including severe maternal illness, premature birth, and serious or fatal neonatal infection — are in most cases substantially greater than any theoretical vaccine risk.
If you have concerns or specific medical conditions, discuss them with your midwife or GP. A personalised conversation is always better than a generalised online search.
What to Expect After Vaccination
Side effects after vaccines in pregnancy are the same as in any adult. Common reactions include:
- Soreness, redness, or mild swelling at the injection site
- Mild tiredness or aching for 1–2 days
- Low-grade fever
- Headache
These reactions are signs the immune system is responding and are not harmful to the pregnancy. They typically resolve within 48 hours. Paracetamol is safe to take in pregnancy to manage fever or discomfort. Avoid ibuprofen in pregnancy unless specifically advised by a doctor.
Serious allergic reactions to vaccines are rare. Remain at the vaccination clinic for 15 minutes after your jab in case of any immediate reaction.
Timing Summary for Each Recommended Vaccine
| Vaccine | Recommended timing |
|---|---|
| Whooping cough (pertussis/Tdap) | 16–32 weeks (up to 38 weeks if missed) |
| Flu | Any time during pregnancy; as early as possible in flu season |
| COVID-19 / booster | When due; recommended throughout pregnancy |
| RSV (Abrysvo) | 28–36 weeks (UK from 28 weeks; US 32–36 weeks) |
Vaccines That Can Be Given After Birth
Some vaccines are better given after birth rather than during pregnancy — particularly for conditions where there is insufficient safety data or where timing after birth is optimal.
The hepatitis B vaccine series can be given postpartum if not already completed. The MMR and chickenpox vaccines should be given after birth to women who are not immune (they are safe while breastfeeding, even though they are live vaccines, because the live virus does not transfer through breast milk in meaningful quantities).
Frequently Asked Questions
Is the pertussis vaccine safe in every pregnancy, even if I had it before?
Yes. The NHS recommends it in every pregnancy because the antibodies passed to each new baby via the placenta are highest when the vaccine is given in the current pregnancy rather than in a previous one. Immunity from a previous vaccination may have waned, and protection for the baby depends on recent maternal vaccination.
Can I have the flu vaccine if I am in my first trimester?
Yes. The NHS and CDC both confirm that the inactivated flu vaccine is safe at any stage of pregnancy, including the first trimester. There is no reason to delay.
Will getting the RSV vaccine during pregnancy affect my baby?
The RSV vaccine is designed to benefit your baby by passing protective antibodies through the placenta. Clinical trial data showed a significant reduction in severe RSV illness in infants born to vaccinated mothers, without safety signals for the pregnancy or baby.
What if I am allergic to eggs? Can I still have the flu vaccine?
Most flu vaccines contain only trace amounts of egg protein. For those with severe egg allergies, specific egg-free flu vaccines are available, and vaccination can be performed in a clinical setting where any reaction can be managed. Discuss your allergy history with your GP or vaccination provider before attending.
Should I delay the COVID booster until after my first trimester?
No. NHS guidance does not recommend delaying vaccination to the second trimester. The first trimester is a period of vulnerability to severe COVID-19 illness, and the evidence does not show that vaccination in the first trimester causes harm.
What vaccines will my baby receive at birth and in the first weeks of life?
In the UK, newborns are offered the hepatitis B vaccine at birth if the mother carries hepatitis B. The standard infant immunisation schedule begins at 8 weeks with vaccines covering diphtheria, tetanus, pertussis, polio, Hib, hepatitis B, meningococcal B, and rotavirus. Maternal vaccination provides a bridge of protection during the gap before this schedule begins.
Key Takeaways
- Inactivated vaccines including flu, pertussis, COVID-19, and RSV are recommended during pregnancy by the NHS, WHO, and CDC — they are safe and protect both mother and baby.
- Live attenuated vaccines (MMR, chickenpox, yellow fever) are contraindicated in pregnancy; inadvertent early vaccination is not a cause for alarm but should be discussed with a midwife.
- The pertussis (whooping cough) vaccine should be given between 16 and 32 weeks in every pregnancy to protect the newborn during their first vulnerable weeks.
- The RSV vaccine, available from 28 weeks in the UK, significantly reduces serious respiratory illness in young infants and is recommended as a routine part of antenatal care.
- The flu vaccine should not be delayed once flu season begins — flu in pregnancy carries real risks including premature birth and hospitalisation.
- Side effects after vaccination (arm soreness, mild fever, tiredness) are normal immune responses and do not indicate harm to the pregnancy.
📋 SOURCES & FACT-CHECKING
This article is compiled and verified against these authoritative sources: - CDC (Centers for Disease Control & Prevention) - WHO (World Health Organization) - ACOG (American College of Obstetricians and Gynecologists) - NHS (National Health Service) - AAP (American Academy of Pediatrics)
Last verified: June 2026
Educational content only. Always consult your pediatrician for medical decisions.
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PregnancySprout Editorial Team
Our editorial team researches every article against primary medical sources — NHS, WHO, NICE, and RCOG guidelines. We are health writers and parents, not doctors; content is reviewed for accuracy but does not constitute medical advice.
✓ Fact-checked against NHS, WHO, and NICE guidelines
