The Therapeutic Goods Administration has approved provisional use of a fourth COVID-19 vaccine, developed by Moderna, which is already in use across much of the world.
Two other vaccines — Pfizer and AstraZeneca — are all ready in use in Australia.
A single-dose vaccine made by Johnson & Johnson has also been approved by the TGA but has not yet been purchased to be used as part of the national rollout.
With Moderna to soon provide enough vaccine doses for 5 million Australians, there are naturally a lot of questions.
Here are some of your most common ones answered.
When will the Moderna vaccine be available in Australia?
The Therapeutic Goods Administration (TGA) on Monday granted provisional approval to the Moderna mRNA vaccine for use in Australians aged 18 and over.
Provisional approval fast-tracks the use of a medication under strict conditions while a pharmaceutical company completes its final clinical trials.
This pathway is reserved for promising life-saving medicine and can reduce the wait time for a drug by up to two years, the TGA says.
Prime Minister Scott Morrison said the first 3 million doses were on track to arrive in September and those doses would go to pharmacies.
Batches of 3 million doses are also due to arrive in October, November and December.
However, those batches will need to be tested before any of the Moderna shots go into Australian arms. It is not yet known how long that could take.
Who will get the Moderna shot?
The TGA says Australians aged over 18 can get the Moderna vaccine, however, the federal government is yet to set any eligibility requirements for it.
Of the 25 million doses Australia has ordered, 10 million will be for primary vaccination and 15 million will be for booster shots.
Moderna’s vaccine uses the same mRNA technology as the Pfizer vaccine, and has not been associated with the extremely rare blood clotting disorder that a small number of people have developed after receiving the AstraZeneca jab.
Last month, the head of Australia’s vaccine taskforce, Lieutenant General John Frewen, said the introduction of the Moderna shot could allow younger Australians to choose which vaccine they wanted to receive as eligibility opened up.
Does the Moderna vaccine require two doses?
Yes. Like the other vaccines approved for use in Australia, the Moderna formula requires two doses to fortify your immune system against COVID-19.
The doses are recommended to be administered four weeks apart, compared to the three-week interval between Pfizer shots and the eight to 12 week length between AstraZeneca shots, a period which is shortened to between four and eight weeks for people in severely affected areas such as Sydney.
What is its efficacy?
The World Health Organization says studies have shown Moderna’s vaccine is 94.1 per cent effective at preventing symptomatic COVID-19.
Moderna says its shot remains 93 per cent effective six months after the second dose.
All vaccines provide extremely good protection against hospitalisation and death.
Where is it manufactured?
Moderna is a US company and its vaccine is manufactured in the United States before being shipped around the world.
Lonza, a Swiss manufacturer, also produces the Moderna vaccine for European markets.
Is it safe for pregnant women? What about young people?
The World Health Organization says inoculation with the Moderna vaccine is suitable for pregnant women where the benefits outweigh the risks.
The current health advice in Australia is that women be offered the Pfizer vaccine at any stage of pregnancy.
Like the Pfizer vaccine, the Moderna shot is expected to also be approved for children aged 12 and older, but that will have to happen through a separate process.
Moderna has also flagged Australia as a potential site for vaccine trials in children as young as six months.
However, there is little detail on those trials as yet.
What are the common side effects?
In the US, the Food and Drug Administration has reported a range of minor side effects experienced by Moderna shot recipients, more commonly after their second dose of the vaccine.
They include a fever, chills, pain at the injection site, fatigue, muscle or joint pain, headache, swollen lymph nodes or nausea and vomiting.
Which other countries have authorised the Moderna vaccine?
Much of the world has already approved and been using the Moderna vaccine for months.
Nations that have authorised the Moderna vaccine on either a full or emergency basis include the US, the UK, Brazil, Canada, Japan, Israel, Indonesia, Singapore, Pakistan and India, just to name a few.