Respiratory syncytial virus (RSV)

Key facts

  • Respiratory syncytial virus (RSV) is a common viral infection that spreads easily from person to person. RSV disease can cause serious illness and complications for babies. 

  • The RSV vaccine is recommended for all pregnant women at 28–36 weeks of pregnancy (i.e. in their third trimester).

  • The RSV vaccine is free for all pregnant women in Australia.

  • Having the RSV vaccine during pregnancy is safe for both babies and mothers.

  • Certain babies may be recommended to receive additional protection from an infant RSV immunisation product (RSV-specific monoclonal antibody).

Last updated on 6 February 2025.

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What is RSV?

Respiratory syncytial virus (RSV) is a common viral infection. In Australia, almost all children will catch RSV at least once within their first 2 years of life.1 

RSV can be very severe. Babies under the age of 6 months have a higher risk of developing serious complications from RSV and are more likely than older children to end up in hospital due to RSV disease.2 

RSV usually begins with a runny nose, cough, sore throat, fever, wheezing and difficulty breathing. If it progresses, it can also cause complications such as pneumonia and bronchiolitis. More serious complications, such as secondary bacterial infections, can also occur.

RSV spreads very easily from one person to another through the air. When someone who already has the disease coughs or sneezes, the RSV germs pass through the air in tiny droplets. If you breathe in those droplets, you can catch RSV, too. These droplets can also land on surfaces, where the virus can live for several hours.

Yes. Almost all children experience at least one RSV infection within their first 2 years of life.1 While you can catch RSV at any time, it is more common in autumn and winter (around April–September).3

What happens when you catch RSV?

RSV can be unpleasant for adults, and it can be very serious for babies.

Babies – especially babies under the age of 6 months – are more at risk of developing serious complications from RSV and are more likely than other children to end up in hospital for treatment.2 Those serious complications include pneumonia and bronchiolitis.

Signs that a baby is developing RSV complications include:

  • fast breathing or breathing difficulties
  • wheezing
  • not feeding.

Pregnant women and other adults can get RSV – but in most cases, the disease is less severe. Adults with RSV are likely to experience frequent coughing fits, difficulty breathing, fever, ear infection (otitis media) and sinus pain.4

How can I protect myself and my baby from RSV?

The most effective way to protect your baby against RSV during the first few months of their life is to be vaccinated against RSV while you are pregnant. 

Babies born to mothers who did not receive the RSV vaccine within two weeks of being born can still be protected from RSV. This protection can be provided with another RSV immunisation product, a monoclonal antibody called Beyfortus (nirsevimab). Some babies who are more vulnerable to severe RSV disease are also eligible to get this product, even if their mother has previously received the RSV vaccine. 

Beyfortus (nirsevimab) contains ready-made antibodies that help babies and children fight off a potential RSV infection and prevent severe RSV disease.

This product will be available for free through your state or territory RSV infant protection program. For more information, see State and territory nirsevimab (Beyfortus) infant program summary 2025 [PDF].

When should I be vaccinated?

The best time to have the RSV vaccine is between 28 and 36 weeks of pregnancy. Because this is when the transfer of protective antibodies from you to your baby is most effective, this will provide the best protection for your baby after birth. It is given in one needle, in your arm. 

The vaccine can be delivered anytime from 28 weeks of pregnancy up to delivery. However, babies are not completely protected unless they are born at least two weeks after their mother receives the RSV vaccine.5 If this occurs, the baby is recommended to receive an RSV immunisation product (monoclonal antibody).

No. Right now, pregnant women are only recommended to get 1 dose of an RSV vaccine.

Yes. It is safe to have the RSV vaccine and the pertussis (whooping cough), influenza and COVID-19 vaccines at the same time. 

If you delay having the vaccine until after your baby is born, your baby will not be protected against RSV at birth, since they will not have received protective antibodies during pregnancy.

Having the vaccine during pregnancy means your baby will have the best protection at birth. That’s because the antibodies your immune system produces after the vaccination will cross the placenta to give your baby protection, too.

If you have the vaccine after your baby is born, some of the antibodies your body makes in response to receiving the vaccine will be passed on to your baby through your breastmilk, but it will not be as effective as the protection provided by the antibodies that cross the placenta during pregnancy. Instead, your baby will require their own injection of an RSV immunisation product (monoclonal antibody) for adequate protection.  

Certain babies and children of different ages are eligible for immunisation with an RSV immunisation product in Australia, although criteria vary depending on the state or territory they are living in. (For more information, see State and territory nirsevimab (Beyfortus) infant program summary 2025 [PDF].)

Where do I go to get vaccinated?

The midwife or trained immunisation nurse at your antenatal clinic may be able to give you an RSV vaccine. If not, then 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.

How does the RSV vaccine work?

In Australia, the recommended RSV vaccine for pregnant women (Abrysvo) protects against two types (or strains) of RSV. The vaccine works by ‘training’ your body’s immune system to recognise and get rid of the RSV virus. The vaccine contains tiny fragments of the inactivated RSV virus, called antigens. Inactivated antigens cannot reproduce themselves or cause disease.

When your immune system detects the antigens in the RSV vaccine, it produces antibodies to fight them and get rid of them. Your body usually starts producing antibodies around one or two weeks after you have the vaccine. When you are pregnant, it can take a bit longer. Once the antibodies are circulating in your bloodstream, your immune system is ready to start fighting the disease as soon as it encounters it.

When you have a vaccine during pregnancy, the antibodies your immune system produces will cross the placenta to give your baby protection against the disease, too. 

Having the RSV vaccine between 28 and 36 weeks of pregnancy ensures the antibody transfer occurs at the right time for your baby to be best protected once they are born. After birth, some antibodies can also be passed on through your breastmilk; however, the research is not clear about the level of protection breastmilk offers. 

See ‘How will the vaccine affect my baby?’ for more information

How effective is the vaccine?

RSV vaccination during pregnancy is effective in reducing the risk of severe RSV illness in babies during the first six months of life. Studies have shown it lowers this risk by around 70 per cent.6 

Additionally, babies whose mothers had an RSV vaccine during pregnancy were around 60 per cent less likely to be admitted to hospital with RSV in the first six months of life.6 

Is it safe to get the vaccine when you are pregnant?

Yes. The recommended RSV vaccine is safe for pregnant women and their babies. 

The only medical reason for a pregnant woman not to have the RSV vaccine is if she has previously had an anaphylactic reaction to a component of the RSV vaccine.

No. Research tells us being vaccinated against RSV during pregnancy does not increase the risk of adverse pregnancy outcomes. The rates of pre-term birth after RSV vaccination are being actively monitored.

Is there a risk my baby and I will catch RSV from the vaccine?

No. There is no risk that either you or your baby could catch the disease from the vaccine, because it does not contain a live virus. The RSV vaccine recommended during pregnancy is an inactive vaccine that is not live; it contains only antigens, parts of the virus that cannot reproduce themselves or cause disease. 

Vaccines that contain live viruses or bacteria, such as the measles or chickenpox vaccines, are not given to women during pregnancy.

Will I have a reaction to the vaccine?

Most people who have the RSV vaccine have no reaction at all. Some people have mild reactions that last between 12 and 24 hours and are easily treated at home. These are described below.

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
  • at your nearest emergency department
  • by calling Healthdirect on 1800 022 222.

Some pregnant women get some redness and soreness at the spot where the needle went in.6,7 This is called a local reaction. 

The redness and soreness will get better in a day or two. In the meantime, you can place a cool, damp cloth on the spot to soothe it and take an over-the-counter pain medication, such as paracetamol, if you feel you need one. You should check with your doctor before taking any other pain medications.

Some pregnant women experience a headache after vaccination.6,7

The headache will get better by itself, but you can take an over-the-counter pain medication, such as paracetamol, if you feel you need one.

Some pregnant women develop a fever of 38°C or less.6,7 

If you have a fever after your vaccination, drink plenty of water and consider using some paracetamol to help bring the temperature down. See your doctor if your fever is above 38°C or is prolonged.

Studies have shown that some pregnant women can experience fatigue, nausea, muscle pain, joint pain, vomiting and diarrhoea after RSV vaccination.6,7 These side effects usually lasted only a few days.

Are there any rare and/or serious side effects to the vaccine?

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.8 Midwives, nurses and GPs are trained to respond to an anaphylactic reaction with quick delivery of adrenaline.

No rare adverse events were found in the clinical trials of the RSV vaccine approved for use in Australia – but to be safe, it is only recommended for women at 28 weeks of pregnancy or later.

What else can I do to protect my child from RSV?

If you are not able to get an RSV vaccine during pregnancy, or your baby is: (i) born within two weeks of you receiving the vaccine; or (ii) has a condition that increases their risk of severe RSV disease, then they are eligible for an RSV immunisation product (monoclonal antibody). This will give them more protection from RSV.

It is also sensible to:

  • keep small babies away from people who are sick 
  • encourage anyone in the household who is unwell to cover their mouth when they cough or sneeze and to wash their hands regularly.

  1. Bennett JE, Dolin R & Blaser MJ. Mandell, Douglas, and Bennett’s principles and practice of infectious diseases. 9th ed. Philadelphia: Elsevier; 2019
  2. Lively JY, Curns AT, Weinberg GA, et al. Respiratory syncytial virus-associated outpatient visits among children younger than 24 months. Journal of the Pediatric Infectious Diseases Society 2019;8:284-6 
  3. Price OH, Sullivan SG, Sutterby C et al. Using routine testing data to understand circulation patterns of influenza A, respiratory syncytial virus and other respiratory viruses in Victoria, Australia. Epidemiology and Infection 2019;147:e221 
  4. Falsey AR, Becker KL, Swinburne AJ et al. Bacterial complications of respiratory tract viral illness: a comprehensive evaluation. Journal of Infectious Diseases 2013;208:432-41 
  5. Kong KL, Krishnaswamy S & Giles ML. Maternal vaccinations. Australian Journal of General Practice 2020;49:630-5 
  6. Kampmann B, Madhi SA, Munjal I et al. Bivalent prefusion F vaccine in pregnancy to prevent RSV illness in infants. New England Journal of Medicine 2023;388:1451-64 
  7. National Institutes of Health. A phase 2B placebo-controlled, randomized study of a respiratory syncytial virus (RSV) vaccine in pregnant women. October 2022. Available from: https://classic.clinicaltrials.gov/ct2/show/results/NCT04032093?view=results. (Accessed 13 June 2024). 
  8. McNeil MM, Weintraub ES, Duffy J et al., Risk of anaphylaxis after vaccination in children and adults. Journal of Allergy and Clinical Immunology 2016;137: 868-78