Vaccination and the Immune System in Pregnancy

Vaccines in Pregnancy 

During pregnancy, vaccines are offered to protect against diseases and their complications. These vaccines are chosen as the diseases they help to protect against can cause serious illness to you while pregnant or to your newborn baby. Receiving these vaccines is safe and the best way to protect both mother and baby during this time.

This page provides the following information:

Which vaccines should I get if I am pregnant?

Three vaccines are currently recommended for pregnant individuals in the UK, these are:

1.  The Flu vaccine 

The risk from serious influenza is especially high in pregnancy. Death rates from flu are higher among pregnant individuals than among people who are not pregnant. Flu in the mother is also a risk to the baby, but vaccination protects pregnant people and their babies from these effects. In the 2020-21 flu season, over 43% of pregnant people in England (more than 264,000 people) received the flu vaccine.

2.  The Pertussis (whooping cough) vaccine

Almost all deaths from whooping cough occur in young babies before they have had a chance to be vaccinated. Babies can be protected by vaccinating the mother during pregnancy. In 2020-21, over 67% of pregnant people in England received the whooping cough vaccine.

3.  COVID-19 vaccines

Pregnant people are more at risk of becoming seriously ill from COVID-19 and are at an increased risk of complications such as preterm labour and stillbirth. Almost all pregnant individuals hospitalised or admitted to intensive care with COVID-19 between May-October 2021 were unvaccinated (96%). COVID-19 vaccines are safe and effective in pregnant individuals and protect both mother and child.

Are vaccines safe during pregnancy?

Vaccines against Flu, Pertussis and COVID-19 are safe and recommended for pregnant individuals. Understandably, some pregnant people may be concerned about the effects of the vaccine itself on their unborn baby, but there is no evidence that the recommended vaccines cause any harm to the mother or to the baby. Preventing these serious illnesses and their complications by vaccination has been shown to protect babies from becoming severely unwell in the first few months of life. All vaccines recommended for pregnant people have been thoroughly assessed in clinical studies of pregnant women to ensure they are safe in this group. More information about how vaccines are tested can be found here.

When should I have the vaccines?

Flu vaccines are available to all pregnant people in the UK during the flu season from September to January. The flu vaccine can be given at any stage of pregnancy, however, pregnant individuals are recommended to have their flu vaccine as early as possible in the season to provide the best protection for both mother and baby.

Pertussis (whooping cough) vaccines provide the best protection when given between 16-32 weeks pregnant. If vaccination is missed during this time, it can still be given later in pregnancy, however, the protection provided may not be passed to the baby.

COVID-19 vaccine doses and boosters can be given at any time during pregnancy. Those who have not already received a COVID-19 vaccine should aim to have both doses and the booster as soon as possible. It is not necessary to delay vaccination until after birth. More information on the timing of COVID-19 vaccine doses can be found here

To arrange these vaccinations in the UK, contact your GP or midwife.

Why should I get vaccinated during pregnancy?

During pregnancy, the immune system becomes weakened which can make pregnant people more susceptible to infections and serious illness from certain diseases. These diseases can lead to complications during pregnancy, in the worst cases leading to preterm labour and stillbirth. Vaccination against these diseases is strongly recommended to help protect against infection and associated complications.

Vaccines work to protect us from infection by stimulating the production of protective antibodies by our immune system (find out more here). This protection, in the form of antibodies, can then pass to babies through the placenta or in breast milk. Getting vaccinated while pregnant therefore protects both mother and baby. This is important as babies don’t start to receive their own vaccinations until 8 weeks of age, so this can help protect them until they receive their own vaccines and make their own protective immune responses.  

 


The infographic above shows the importance of antibodies in protecting both mother and baby. Protective antibodies produced by mothers following vaccination, known as vaccine-induced antibodies, can pass to their babies either through the placenta (left) or in their breast milk (right). Antibodies which pass through the placenta (IgG antibodies) remain in infants until approximately six months after birth and play an important role in protection against diseases during these early months of life. Antibodies shared in breast milk (IgA antibodies) also contribute to this line of defence. Antibody levels in breast milk are highest in the first few days after birth when colostrum is produced, but begin to gradually decline as milk matures. Credit: Designed by Dr Sean Elias   

 

Should I delay vaccination until after pregnancy?

For the vaccines indicated above, it is not recommended to delay vaccination until after giving birth – this could pose risks to both mother and developing or newborn baby. Getting vaccinated during pregnancy provides the best possible protection to both mother and child.

Do I need to get revaccinated for each pregnancy?

Even for those who may have received their flu and pertussis (whooping cough) vaccines previously, it is still important to get vaccinated for each pregnancy. This is because over time, immunity from vaccines naturally begins to drop. The flu vaccine also changes each year to target the most common flu strains circulating at the time, so flu vaccines received in the past will not be the same as the ones currently being used. Being revaccinated in each pregnancy increases the protection for both mother and baby.

Why are some vaccines not recommended whilst pregnant?

Vaccines which contain live, weakened versions of an organism (live attenuated vaccines) are typically contraindicated (not recommended) during pregnancy as these have the possibility of causing infection in the baby. The vaccines recommended above are not live vaccines and are not able to cause disease.

Live attenuated vaccines include:

Generally, it is recommended to delay these vaccinations until after giving birth. In some cases where there is a high risk of infection, these vaccines may be given to pregnant people. If you are not sure whether a vaccine is safe for you while you are pregnant, please contact your health professional.

Vaccines for Newborns

Once born, babies can start to receive their own vaccinations from 8 weeks of age. A list of recommended vaccines can be found here. These early vaccines are important as the diseases they protect against are high risk for babies at this young age.

After birth, babies need to have their own vaccinations as the antibodies passed from the mother through the placenta or via breastfeeding are short-lived, known as passive immunity. If a baby does not receive their vaccinations, they will be unable to make their own antibodies and will be left unprotected. If babies receive their vaccinations, they can produce their own immune response which lasts much longer.

Babies are also routinely vaccinated against many other diseases which their mothers are not vaccinated against during pregnancy including hepatitis B, rotavirus and type B meningococcal disease amongst others. It is therefore important for babies to receive these vaccinations to be protected against these additional diseases.

Do I need to have any vaccines If I am trying to become pregnant?

All people who are thinking about becoming pregnant are advised to check that they have been vaccinated against rubella (usually as part of the MMR vaccine). This is because catching rubella in pregnancy can have a very serious effect on the unborn baby (see information on Congenital Rubella Syndrome). It is too late to be vaccinated against rubella once you are pregnant.

Since April 2016, pregnant people in the UK have not been offered screening for rubella susceptibility. Previously, all pregnant individuals were offered a blood test to check whether they were immune to rubella. This change reflects the great success of the MMR vaccine in reducing transmission of the rubella virus to almost zero. MMR vaccination rates are high in the UK, which means that pregnant people are protected from rubella by herd immunity. In 2011, a review by the UK National Screening Committee (UK NSC) found that there were almost no cases of congenital rubella syndrome in the UK (less than 1 case per 100,000 live births). According to World Health Organization criteria, this effectively means the disease has been eliminated. The UK NSC therefore recommended that the screening programme should stop. See the Public Health England statement for more information. Women of child-bearing age will still be offered the MMR vaccine if they have not already had it or are not sure if they have had it.

Vaccines in Development

Group B Streptococcus is the commonest cause of serious infection and meningitis in babies under 3 months old and is usually passed from mother to baby around birth. A vaccine is not yet available for pregnant people, but several are being developed. See more information on Group B Streptococcus.

Page last updated: 
Thursday, May 26, 2022