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Third trimester (27-40 weeks)

Key facts

  • Vaccination against both influenza and whooping cough is recommended for all pregnant women, in each pregnancy.

  • Women who have not yet had these vaccinations are able to do so in their third trimester.

  • Both vaccines are free for all pregnant women in Australia.

Last updated on 25 April 2023.
What vaccines are recommended in my third trimester?

Whooping cough

When you are pregnant, it is strongly recommended that you get vaccinated against whooping cough (also known as ‘pertussis’). Ideally you should have the vaccination between 20 and 32 weeks. This is when the vaccine provides the most effective protection for your baby. However, the vaccine can be delivered anytime from 20 weeks, up to delivery.3

The whooping cough vaccine will protect both your baby and you from this serious infectious disease. Studies indicate that nine out of ten babies under three months of age are protected against whooping cough if their mothers received the whooping cough vaccine during pregnancy.1,2

The influenza (or ‘flu’) vaccine is recommended at any time in pregnancy. Getting vaccinated against influenza protects both you and your baby from one of the most common and highly contagious viral infections. Babies can’t be vaccinated against influenza until they are six months old. Until then, the vaccine you get during pregnancy will provide the best early protection from the influenza virus.

Both vaccines are free for all pregnant women in Australia. It is recommended that you get both vaccines, each time you are pregnant. It is safe to have both vaccines at the same time.

What do I need to do before the vaccination?

There’s no need to do anything special to get ready for your vaccination.

The best time to have the whooping cough vaccination is between 20 and 32 weeks of pregnancy. This is when the transfer of protective antibodies from you to your baby is most effective and will provide the best protection for your baby after birth. However, the vaccine can be delivered anytime from 20 weeks of pregnancy up to delivery.3

You can get the influenza vaccination at any time during your pregnancy, and at any time of the year. 

The midwife or trained immunisation nurse at your antenatal clinic may be able to vaccinate you against whooping cough and influenza. If not, you can go to your GP or your local council clinic. Most GPs will need you to make an appointment if you require a vaccine.

What do I need to do after the vaccination?

Most people have no reaction to either the whooping cough vaccine, or the influenza vaccine. Some people have mild reactions that last between 12 and 24 hours and are easily treated at home. 

If your symptoms last longer than a couple of days, or if you are worried about how you feel after your vaccination, you can get help from your doctor, or your nearest emergency department, or by calling Health Direct on 1800 022 222.

A very small number of people have a severe allergic reaction to vaccines called ‘anaphylaxis’, where they can develop swelling, hives, breathing difficulties, lowered blood pressure and in severe cases, shock. Anaphylactic reactions are very rare – they occur in about one in a million people who have a vaccination.4 Midwives, nurses and GPs are trained to respond to an anaphylactic reaction with quick delivery of adrenaline.

Read more about the rare but serious side effects >

When do I need my next vaccination?

You do not need to have any further vaccinations during your pregnancy once you have been vaccinated against whooping cough and influenza.

It is highly recommended that your baby has the hepatitis B vaccine soon after birth. 

What if I still have questions?

You can find more information on vaccination in pregnancy and at birth in our Resources section, and on these pages:

If you still have some questions remaining, write them down so that you can ask your midwife, nurse or GP at your next appointment.

  1. Amirthalingam, G., Andrews, N., Campbell, H., et al., Effectiveness of maternal pertussis vaccination in England: an observational study. Lancet, 2014. 384(9953): p. 1521-8.
  2. Baxter, R., Bartlett, J., Fireman, B., Lewis, E., and Klein, N.P., Effectiveness of Vaccination During Pregnancy to Prevent Infant Pertussis. Pediatrics, 2017. 139(5).
  3. Australian Technical Advisory Group on Immunisation (ATAGI). The Australian Immunisation Handbook [Electronic book] 2018; Available from: 
  4. McNeil, M.M., Weintraub, E.S., Duffy, J., et al., Risk of anaphylaxis after vaccination in children and adults. J Allergy Clin Immunol, 2016. 137(3): p. 868-78.