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Friday, March 29, 2024

What’s really in a COVID-19 vaccine?

So, what’s really in a COVID-19 vaccine? Potassium? Phosphate? Sodium? We explain everything you need to know about the two vaccines approved by Australia’s Therapeutic Goods Administration (TGA).

The ingredient list in a vaccine looks a little more complicated than a packet-mix birthday cake, so it can be a little intimidating at first. But don’t fear, we’ve got all the information you need to make a safe and informed choice.

From polio to whooping cough, tuberculosis and tetanus, Australia has had vaccinations for all sorts of things for more than a century.

They might all look a little different, but they’re all more alike than they are dissimilar.

In fact, many ingredients found in vaccines are also commonly found in your pantry and many are just used to make the vaccine last longer in storage. Other parts of the vaccine are things already inside you, like water and salt.

The main ingredient in all vaccines is plain and simple water.

There are two main vaccines Australians will be receiving this year for COVID-19. These are made by Pfizer and AstraZeneca.

Pfizer

The Pfizer vaccine was the first to be approved by the TGA, and the first to be made available to the Australian Government. It is a little harder to transport, store and deliver, so it will only be made available through Pfizer ‘hubs’, with the Commonwealth Department of Health providing a Pfizer vaccine roll-out to other specific high risk members of the community (eg: aged Care facilities).

Pfizer stocks are limited worldwide and is in very high demand having been used to start vaccination programs in the UK and Europe.

So what does the content of the vaccine look like?

mRNA (messenger ribonucleic acid)

What is mRNA? This is the active ingredient. The only active ingredient, actually. This is where the genetic material for the virus is stored. The mRNA will assist in teaching your own body how to develop an immune response to the COVID19 virus. But rest assured, it’s not a live part of the virus. It’s more like a set of instructions.

Lipids

What’s a lipid? Think of fats, oils and waxes. Lipids don’t dissolve in water, but they help other things move around. We use lipids in almost every part of our bodies functions every day. In the Pfizer vaccine, lipids are used to help the mRNA move into cells.

What does a lipid look like on an ingredient list?

  • ((4-hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2-hexyldecanoate)
  • 2-[(polyethylene glycol)-2000]-N,N-ditetradecylacetamide
  • distearoylphosphatidylcholine
  • cholesterol

Salts

We know what salts are – we use sodium chloride (kitchen salt) for cooking. These salts are in vaccines to help balance out any acidity in the solution so it is more stable for storage and ultimately compatible with the body tissue we inject it into.

What does salt look like on an ingredient list?

  • potassium chloride
  • monobasic potassium phosphate
  • sodium chloride
  • dibasic sodium phosphate dihydrate

Sugar

Simple sugar. The same one you put in your coffee in the morning (or don’t). Sugar is used in vaccines to stop the molecules from losing their shape during the intense freezing process.

What does sugar look like on an ingredient list?

  • sucrose

And there you have it, a whole vaccine.

AstraZeneca

AstraZeneca has also been approved by the TGA, and is now available in Australia. Not only that, but Australia will be producing its own supply of the AstraZeneca vaccine.

Because AstraZeneca is easier to store, move and share, its availability will allow for a much broader distribution of vaccine, and more locations will come online, including more hospitals, GPs and pharmacies.

Most Australians will be receiving the AstraZeneca vaccine.

So what does the content of the vaccine look like?

Modified virus (adenovirus)

This is the vaccine active ingredient. Adenoviruses are a group of common viruses that can cause a variety of illnesses (e.g. Bronchitis, conjunctivitis). Most people will have been exposed to some kind of adenovirus in their lifetime. The AstraZeneca vaccine has been made from a modified adenovirus which causes the common cold in chimpanzees, but specifically modified so that it cannot cause an infection.

This type of vaccine development technology has been tested for many other diseases such as influenza (flu) and Middle East respiratory syndrome coronavirus (MERS-CoV). It sounds a little scary, but it’s anything but new.

Emulsifiers

Some vaccines contain both oil and water-based ingredients, and we all know the two do not easily go together. Vaccine developers will add emulsifiers to help the oil and water-based ingredients stay together, like adding lemon to a mayonnaise recipe.

What does an emulsifier look like on an ingredient list?

  • polysorbate 80

Preservatives

Since vaccines go into the body, it’s pretty important to keep them clear of any contamination.

Some vaccines come in multi-dose vials, so there is an increased risk of introducing contamination, like bacteria, each time a needle enters the vial. Tiny amounts of anti-microbial ingredients are added to the vials to protect the vaccine and you, as a result, making the vaccines safer to use.

What does a preservative look like on an ingredient list?

  • disodium edetate dihydrate
  • ethanol (at less than 0.005% – remember that a regular beer is 1000 times stronger than that at around 5%)

Lipids

What’s a lipid? Think of fats, oils and waxes. Lipids don’t dissolve in water, but they help other things move around. We use lipids in almost every part of our bodies functions every day. In the AstraZenica vaccine, lipids are used to help the active part of the vaccine work more effectively.

What does a lipid look like on an ingredient list?

  • L-histidine
  • L-histidine hydrochloride monohydrate
  • magnesium chloride hexahydrate

Sugar

Simple sugar. The same one you put in your coffee in the morning (or don’t). Sugar is used in vaccines to stop the molecules from losing their shape during the production process.

What does a sugar look like on an ingredient list?

  • sucrose

Salt

We know what salts are – we use sodium chloride (kitchen salt) for cooking! These salts are in vaccines to help balance out any acidity in the solution so it is more stable for storage and ultimately compatible with the body tissue we inject it into.

What does a salt look like on an ingredient list?

  • sodium chloride

And that’s it!

What about allergies?

For those worried about their allergies, the Pfizer and AstraZeneca vaccines do not contain human or animal products, or common allergens such as latex, milk, lactose, gluten, egg, maize/corn, or peanuts.

Allergic reactions to vaccines or their ingredients are very rare, but they do happen. In the US, a report from the Centres for Disease Control and Prevention (CDC) suggested that severe allergic reaction (anaphylaxis) was very rare at 11.1 instances per million doses of vaccine, and that more than 80% of those cases occurred in people with a history of allergic reactions.

You must not get a COVID-19 vaccine if you have had any of the following:

  • Anaphylaxis (a severe allergic reaction) to a previous dose of the same COVID-19 vaccine
  • Anaphylaxis after exposure to any ingredient of the COVID-19 vaccine.

If you have ever had a severe allergic reaction or anaphylaxis to anything else, including after receiving a vaccine, you can still get the vaccine, but you must tell the immunisation provider beforehand.

Vaccines are usually delivered in a healthcare setting by trained professionals who have the right medications and equipment on hand and know what to do if there is an issue.

If you are asked to wait around for 30 minutes after your vaccination, don’t be alarmed. This is a standard procedure, depending on your medical history.

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