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Immunization & pregnancy

Date last reviewed: 
Thursday, Dec 21, 2023

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Immunization is an important part of a healthy pregnancy. It helps protect you and your baby against serious diseases.

Immunization before pregnancy

It’s best to make sure all of your routine immunizations are up to date before becoming pregnant. This is important because some vaccines cannot be given during pregnancy but provide important protection. For example, the measles, mumps, rubella (MMR) vaccine should not be given during pregnancy (and should be given at least 4 weeks before becoming pregnant), but rubella infection during pregnancy can cause miscarriage and serious birth defects. 

It's also important to make sure that everyone in your household is up to date with their immunizations. This lowers the chance of a household member getting a vaccine-preventable disease and passing it on to you or your baby. 
Check with your health care provider to make sure your immunizations are up to date.

Immunization during pregnancy

It is recommended that pregnant people get vaccinated against:
  • Pertussis (whooping cough) in every pregnancy.
  • Influenza (flu) if you are pregnant during influenza season.
  • COVID-19 if you are not up to date on your COVID-19 vaccines. 

Other vaccines may be recommended if you are travelling or at risk for certain diseases.

Influenza (flu) vaccine 

It’s recommended that all pregnant people at any stage of pregnancy get an influenza (flu) vaccine during the influenza season. Pregnant women should get the influenza vaccine given by injection (flu shot), not the live attenuated vaccine (given as a nasal spray). Here's why influenza immunization in pregnancy is important:
  • Changes in the immune system, heart, and lungs during pregnancy make a person more prone to severe illness and hospitalization from influenza. 
  • Influenza can be harmful to a pregnant person’s developing baby. It can lead to serious pregnancy complications, including the risk of premature labour and delivery.
  • Evidence shows that infants born during the influenza season to people immunized during pregnancy are less likely to be premature, small for gestational age, or of low birth weight. 
  • When a pregnant person gets the influenza vaccine, they pass protective antibodies along to their baby that can help protect the baby from influenza for several months after birth. This is important because babies can get really sick from influenza but can’t get the vaccine until they are six months old. 
Two pregnant woman talking on a blue couch.
Pertussis (whooping cough) vaccine 
It is recommended that pregnant people get the pertussis vaccine in every pregnancy. The pertussis vaccine is given as the tetanus, diphtheria, and pertussis (Tdap) vaccine. This vaccine is free for pregnant people. Here's why pertussis immunization in pregnancy is important: 
  • Pertussis can be very dangerous for babies. It can make it hard for babies to breathe and can be deadly. The younger a baby is when they get pertussis, the more likely they will need to be treated in a hospital. However, babies are not offered the pertussis vaccine until they are two months old.
  • The best way to protect your baby from pertussis and its complications during the first months of life is to get the vaccine during your pregnancy. When you get the pertussis vaccine, your body creates protective antibodies, and you pass some of them to your baby before birth. These antibodies will provide your baby with some short-term, early protection against pertussis.
The best time to get the pertussis vaccine is between 27 and 32 weeks of pregnancy. This gives enough time for you to pass the protective antibodies on to your baby. However, the vaccine may be given earlier and can be given up until delivery. Talk to your health care provider about timing.

Other vaccines 

In certain situations, other vaccines may be recommended during pregnancy. 
Some examples:
  • The hepatitis B vaccine may be recommended for a pregnant person whose job, lifestyle, or health history puts them at high risk of hepatitis B infection. 
  • The hepatitis A, meningococcal, and polio vaccines may be recommended for pregnant people travelling to countries where these diseases are common. Tell your health care provider if you are travelling outside Canada during your pregnancy.

COVID-19 vaccine

If you are pregnant and not up to date on your COVID-19 vaccine, you should get vaccinated. Getting the COVID-19 vaccine helps protect you and your baby.
  • Pregnant people are at increased risk of serious illness and complications from COVID-19 infection. Vaccines can drastically reduce this risk and can be given safely at any time while trying to conceive, during pregnancy or while breastfeeding.
  • Pregnant people who have been vaccinated against COVID-19 are much less likely to end up in the hospital or ICU, have a premature birth, or have their baby admitted to the NICU for COVID-19 compared to those who don’t get vaccinated (this data is based on people who have had two or more COVID-19 vaccines). 
  • Studies have shown that pregnant people who get a COVID-19 vaccine receive the same levels of protection that non-pregnant people do and that this protection can be passed on to your baby.
The Canadian Society of Obstetrics and Gynecology (SOGC), the National Advisory Committee on Immunization (NACI), and public health experts in BC all agree that pregnant and breastfeeding people should get the COVID-19 vaccine.

Safety of vaccines during pregnancy

The Tdap, inactivated influenza, and COVID-19 vaccines are safe for pregnant people and their babies. 
  • The inactivated influenza vaccine has been given to millions of pregnant people over many years. There is good evidence to show it is safe for pregnant people and their babies.
  • Many studies have been done on the tetanus, diphtheria, and pertussis (Tdap) vaccine, showing that it is safe for pregnant people and their babies.
  • Evidence from around the world continues to grow and has not found any safety concerns for pregnant people who were vaccinated against COVID-19 or for their babies. There are currently no known serious risks (such as an increased risk of miscarriage or possible birth defects) when getting a COVID-19 vaccine while pregnant.
These are non-live vaccines. Non-live vaccines are generally considered safe in pregnancy. However, the HPV vaccine should not be given during pregnancy because data on the efficacy and safety of HPV immunization in pregnancy are limited.
Live vaccines (for example, measles, mumps, rubella (MMR), and chickenpox (varicella) vaccines) contain a weakened version of the living viruses. In general, live vaccines should not be given in pregnancy because there is a theoretical risk of infection of the fetus. However, to date, no significant adverse effects to the fetus following MMR or varicella vaccination have been reported. If a pregnant person inadvertently receives the MMR or varicella vaccine, it is not a reason to terminate the pregnancy. 
Your health care provider can tell you which vaccines are recommended for you and which are safe to get during pregnancy.

Immunization after pregnancy

If you didn’t catch up on certain vaccines before or during pregnancy, get them as soon as possible after your baby is born. This will help protect you and your baby by lowering the chance of you getting a vaccine-preventable disease and passing it on to your baby. It will also ensure you’re protected in future pregnancies. 
In general, routinely recommended vaccines are safe for breastfeeding people and their infants. However, some less common vaccines, such as yellow fever, should not be given while breastfeeding.
A newborn hand holding an adults hand.