About the COVID-19 Vaccine

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 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.

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 the side effects of the COVID-19 vaccines?

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.

Common reactions to the COVID-19 vaccines 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.

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.

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.

An extremely rare blood clotting syndrome, Thrombosis with Thrombocytopenia Syndrome (TTS), has been linked to the AstraZeneca vaccine. More information about TTS can be found below.

What is Thrombosis with Thrombocytopenia (TTS)?

Thrombosis with Thrombocytopenia Syndrome (TTS) is a rare side effect of the AstraZeneca COVID-19 vaccine. It is extremely rare, can be very serious and can cause long-term disability and death.

Thrombosis is the formation of a blood clot, which prevents blood flowing normally through the body.

Thrombocytopenia is a condition in which you have a low blood platelet count. Platelets (thrombocytes) are blood cells that help blood clot. Platelets stop bleeding by clumping and forming plugs in blood vessel injuries.

TTS typically occurs around 4 to 28 days after vaccination with AstraZeneca COVID-19 vaccine.

If you experience the following symptoms after your AstraZeneca COVID-19 vaccination you should seek medical attention immediately:

  • A severe persistent headache with additional features:
    • appears at least 4 days after vaccination
    • does not improve with simple painkillers
    • may be worse when lying down
    • may be accompanied by nausea and vomiting
  • Neurological symptoms such as:
    • blurred vision
    • difficulty with speech
    • drowsiness
    • seizures
  • Shortness of breath
  • Chest pain
  • Swelling in your leg
  • Persistent abdominal (belly) pain
  • Tiny blood spots under the skin away from the site of injection.

More information about TTS can be found on the Australian Government Department of Health website. 

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.

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
  • you experience any side effects associated with TTS.

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 SA COVID-19 Information Line on 1800 253 787 9.00am to 5.00pm, 7 days a week.

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.

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.