About the COVID-19 Vaccine

Following a review of the use of the COVID-19 AstraZeneca vaccine, the Australian Technical Advisory Group on Immunisation (ATAGI) recommends that the COVID-19 vaccine by Pfizer is preferred over the COVID-19 vaccine by AstraZeneca in adults aged under 50 years. Find out more.

Why is the vaccine important?

COVID-19 can cause serious illness, ongoing health conditions, and sometimes death.

The vaccines are designed to ensure that if you do catch COVID-19, you do not get seriously ill.

There is also growing evidence that vaccinated people are less infectious if they do catch COVID-19. This means getting vaccinated is the best way you can protect yourself, your loved ones and our community.

How do the COVID-19 vaccines work?

The COVID-19 vaccines work by preparing the body to defend itself against COVID-19.

When a person is given the Pfizer COVID-19 vaccine, some of their cells will read the vaccine’s mRNA instructions and temporarily produce the spike protein, which mimics the COVID-19 virus. The person’s immune system will then recognise this protein as foreign and produce antibodies and activate T cells (white blood cells) to attack it.

When a person is given the AstraZeneca COVID-19 vaccine, some of their cells will be “infected” by a dead adenovirus (common cold) carrying the DNA for the spike protein, which mimics the COVID-19 virus. The person’s immune system will then recognise this protein as foreign and produce antibodies and activate T cells (white blood cells) to attack it.

Once vaccinated, if a person comes into contact with COVID-19, their immune system will recognise it and be ready to defend the body against it having already been exposed to the vaccine.

As a result, you will be less likely to have severe COVID-19 symptoms after a vaccination.

How do the COVID-19 vaccines protect me?

The goal of vaccination is to stop you from getting sick.

The COVID-19 vaccines train your immune system to recognise COVID-19. They have been designed to help you fight off COVID-19 before it makes you sick, and to reduce the severity of your symptoms if you do get sick.

Most vaccines work in this way. This is why it’s so important that everyone gets vaccinated.

During clinical trials of the COVID-19 vaccines, research focussed on whether the vaccines helped produce enough antibodies to stop us from getting sick. The ones that did this safely and effectively have been approved for use.

Now that the vaccines are being rolled out world-wide, early research suggests they may also be able to reduce how infectious we are if we do catch COVID-19, which could help stop or reduce the spread of the virus.

It is very important that we continue practising good hygiene, using the COVID Safe Check In, physical distancing, and getting tested and staying home if you are unwell, especially during the roll out of the vaccination program.

What’s in the COVID-19 vaccines?

Vaccine ingredients vary depending on what the vaccine is for. Generally, vaccines may contain some of the following ingredients:

  • a protein component of a virus
  • a piece of genetic code (DNA or mRNA)
  • a very small dose of a weakened virus
  • a substance to boost the immune response (an adjuvant)
  • a small amount of preservative
  • sterile salt water (saline) for injections

Ingredients for the COVID-19 vaccines approved for use in Australia will be listed in the Australian Register of Therapeutic Goods.

Do the vaccines contain any animal products?

The approved COVID-19 vaccines do not contain any animal products or egg.

Can the vaccine give me COVID-19?

No, the COVID-19 vaccines available do not use the live or whole virus that causes COVID-19.

Can I catch COVID-19 even if I’ve had the vaccine?

Yes. The goal of vaccination is to stop you from getting sick. The COVID-19 vaccines train your immune system to recognise COVID-19. They have been designed to help you fight off COVID-19 before it makes you sick, and to reduce the severity of your symptoms if you do get sick.

Most vaccines work in this way. This is why it’s so important that everyone gets vaccinated.
There’s growing evidence that vaccinated people are less infectious if they do catch COVID-19, which means getting vaccinated is the best way you can protect yourself and your loved ones.

It’s also important to continue practising good hygiene, using the COVID SAfe Check-In, physical distancing, and getting tested and staying home if you are unwell, especially during the roll out of the vaccination program.

If I catch COVID-19 after I have the vaccine, can I pass the infection onto others?

Early research indicates that the vaccines may be able to reduce how infectious we are if we do catch COVID-19. The Therapeutic Goods Administration (TGA) will continue to monitor the ongoing research to understand whether the vaccines can stop a person passing the virus onto another person.

This is why it’s important that even if you have been vaccinated, you should continue practising good hygiene, using the COVID SAfe Check-In, physical distancing, and getting tested and staying home if you are unwell.

Do I still need to practice hand hygiene and physical distancing even if I've been vaccinated?

It is very important that we continue practising good hygiene, using the COVID SAfe Check-In, physical distancing, and getting tested and staying home if you are unwell, especially during the roll out of the vaccine program, which will take several months.

Australia will still need to have the flexible strategies already in place to control COVID-19. If the vaccine program is effective and results in a high proportion of people being vaccinated, it is hoped that we will be able to reduce some of these control measures. This is likely to be a slow process and will rely on many people being willing to have the vaccine.

How long does the vaccine protect me from getting COVID-19?

Clinical trials have shown that the COVID-19 vaccines protect against COVID-19 symptoms and severe disease after a person receives two doses. At this stage, there is not enough information to understand the long term protection against COVID-19 after vaccination. Booster doses may be required, similar to other vaccinations, such as the flu vaccine.

The Therapeutic Goods Administration (TGA) will continue to monitor the ongoing research to understand how the vaccines work over time. This is why it’s important that even if you have been vaccinated, you should continue practising good hygiene, using the COVID SAfe Check-In, physical distancing, and getting tested and staying home if you are unwell.

Will the vaccine reduce the spread of transmission of the virus?

The COVID-19 vaccines train your immune system to recognise COVID-19. They have been designed to help you fight off COVID-19 before it makes you sick, and to reduce the severity of your symptoms if you do get sick.

Most vaccines work in this way. This is why it’s so important that everyone gets vaccinated.
During clinical trials of the COVID-19 vaccines, research focussed on whether the vaccines helped produce enough antibodies to stop us from getting sick. The ones that did this safely and effectively have been approved for use.

Now that the vaccines are being rolled out world-wide, early research suggests they may also be able to reduce how infectious we are if we do catch COVID-19, which could help stop or reduce the spread of the virus.

It is very important that we continue practising good hygiene, using the COVID SAfe Check-In, physical distancing, and getting tested and staying home if you are unwell, especially during the roll out of the vaccination program.

Do I still need to quarantine when I arrive in Australia if I've been vaccinated overseas?

Anyone travelling to Australia from overseas will still need to quarantine for 14 days upon arrival, even if they’ve been vaccinated against COVID-19.

If you’re coming to Australia, you also need to have a negative COVID-19 polymerase chain reaction (PCR) test result 72 hours or less before the scheduled departure time of your flight (or your first flight if you have a connecting flight during your journey to Australia).

You need to provide evidence of your negative result when you check in at the airport and carry this while you're travelling.

There are a few exemptions from pre-departure testing — such as where PCR testing is not reasonably available.

When will I be able to travel after getting the vaccine?

It is expected that travel will resume when enough of the global population has been vaccinated against COVID-19. You can do your part to speed things up by getting vaccinated when it’s your turn.

At some point, our international borders will open again. With that comes an increased risk that COVID-19 will become active in our community. Now is the time to prepare for the future and ensure that we’re all protected and ready for international travel. For more information, visit Smart Traveller.

Are there any side effects?

Vaccines, like any other medication or natural therapy, can have reactions or side effects. The extent and severity of side effects of the COVID-19 vaccines are similar to those from other vaccines. As part of regulatory assessment of all vaccines, the Therapeutic Goods Administration (TGA) considers information about possible side effects. For a vaccine to be registered for use in Australia, the benefits must outweigh the risks.

You may experience minor reactions or side effects following vaccination. Most reactions or side effects last no more than a couple of days and do not require special treatment. Serious reactions like allergic reactions are extremely rare.

Vaccines are monitored for a long time and even after a vaccine is given, it is still monitored for safety. Healthcare professionals contribute to ongoing monitoring by informing the TGA of any side effects, even if they are very minor. This means the TGA can oversee the safety of a vaccine across the country and, in the unlikely event that there is a safety risk, inform healthcare providers, the community and the Government as soon as possible.

Common reactions to the COVID-19 vaccine include:

  • tenderness, pain and swelling at the injection site
  • tiredness
  • headache
  • muscle and joint pain
  • chills
  • fever.

Some people may also experience redness at the injection site, nausea, itching at the injection site, pain in the limb, enlarged lymph nodes, difficulty sleeping or generally feel unwell.

An extremely rare blood clotting syndrome, Thrombosis with Thrombocytopenia Syndrome (TTS), has been linked to the AstraZeneca vaccine.

The clotting condition occurs between four and 20 days after the first dose of vaccine. During this time, please seek medical attention immediately if you experience any of the following symptoms:

  • shortness of breath
  • chest pain
  • swelling in your leg
  • persistent abdominal (belly) pain
  • neurological symptoms, including severe and persistent headaches or blurred vision
  • tiny blood spots under the skin beyond the site of injection.

You can use the COVID-19 Vaccine Side Effect Checker if you have concerns about any symptoms after having either of the COVID-19 vaccines.

If you have any general questions or concerns, you can also call the National COVID-19 Vaccine Helpline 24 hours a day on 1800 020 080.

Reporting reactions and side effects is an essential part of ensuring ongoing vaccine safety monitoring. If you experience side effects from the vaccine, you can let your vaccine provider know and they can report them on your behalf.

Why do vaccines cause reactions or side effects?

Reactions or side effects, such as fever and tiredness, from vaccines are often a really good sign that your immune system has been activated and is learning how to fight the disease you’ve been vaccinated against.

What are some of the common side effects I might experience after my COVID-19 vaccine?

You may experience some side effects following vaccination. Most side effects last no more than a couple of days and you will recover without any problems.

Common reactions to vaccination include pain, redness and/or swelling where you received the needle, mild fever, headache and flu-like symptoms.

Serious reactions such as allergic reactions are extremely rare.

You can use the COVID-19 Vaccine Side Effect Checker if you have concerns about any symptoms after having either of the COVID-19 vaccines.

If you have any general questions or concerns, you can also call the National COVID-19 Vaccine Helpline 24 hours a day on 1800 020 080.

What should I do if I have had a bad reaction to the COVID-19 vaccine?

As with any medication, very rarely a severe allergic reaction may occur. If it does, it will generally occur within 15 minutes of the vaccination.

If a reaction or side effect seems severe or persists for more than 3 or 4 days, you develop new or unexpected symptoms, or you are concerned, seek medical attention.

You can use the COVID-19 Vaccine Side Effect Checker if you have concerns about any symptoms after having either of the COVID-19 vaccines.

If you have any general questions or concerns, you can also call the National COVID-19 Vaccine Helpline 24 hours a day on 1800 020 080.

Reporting reactions and side effects is an essential part of ensuring ongoing vaccine safety monitoring. If you experience side effects from the vaccine, you can let your vaccine provider know and they can report them on your behalf.

I’m concerned that I’ve had a bad reaction to the COVID-19 vaccine - when should I seek medical attention?

See your doctor or health care professional as soon as possible or go directly to a hospital if:

  • you have a reaction that you consider severe or unexpected
  • you are concerned about your condition after vaccination.

Seek medical attention immediately if you experience any of the following symptoms:

  • shortness of breath
  • chest pain
  • swelling in your leg
  • persistent abdominal (belly) pain
  • neurological symptoms, including severe and persistent headaches or blurred vision
  • tiny blood spots under the skin beyond the site of injection.

Do the COVID-19 vaccines work on new variants?

It is anticipated that the COVID-19 vaccines will be effective against the newer strains of COVID-19.

This is because the vaccines work by inducing what is known as a "polyclonal" response – a collection of immunological responses to many different parts of the COVID-19 "spike" protein. In the new variants, only a limited part of the spike protein is changed, and much is unchanged, so the vaccines should still work against the main, unchanged parts to the COVID-19 spike protein.

The Australian Government will continue to closely monitor developments and do their own genetic examination of any local cases.

Do the COVID-19 vaccines cause blood clots?

Thrombosis with Thrombocytopenia Syndrome (TTS) is a rare and new syndrome which has been reported after being given the AstraZeneca COVID-19 vaccine. It may be caused by this vaccine. The condition involves blood clots (occurring in body sites like the brain or abdomen) together with low platelet levels.

The condition is extremely rare, affecting an estimated four to six people for every million people who receive the first dose of the vaccine.

ATAGI recommends that the COVID-19 vaccine by Pfizer is preferred over the COVID-19 Vaccine by AstraZeneca in adults aged under 50 years. This recommendation is based on the increasing risk of severe outcomes from COVID-19 in older adults (and hence a higher benefit from vaccination) and a potentially increased risk of thrombosis with thrombocytopenia following AstraZeneca vaccine in those under 50 years.

COVID-19 Vaccine AstraZeneca can be used in adults aged under 50 years where the benefits are likely to outweigh the risks for that individual and the person has made an informed decision based on an understanding of the risks and benefits.

People who have had the first dose of COVID-19 Vaccine AstraZeneca without any serious adverse effects can be given the second dose, including adults under 50 years.