Australia’s medical regulator has approved the Oxford University-AstraZeneca coronavirus vaccine for use in Australia.

It is the second vaccine given the green light by the Therapeutic Goods Administration after it approved the Pfizer vaccine in January.

In a statement on Tuesday, the TGA said it had approved the vaccine for use in people aged over 18 years.

It said while people over the age of 65 “demonstrated a strong immune response” to the vaccine, there were not enough people infected by COVID-19 in the clinical trials to determine the overall efficacy for that age group.

“The decision to immunise an elderly patient should be decided on a case-by-case basis, with consideration of age, co-morbidities and their environment taking into account the benefits of vaccination and potential risks,” it said.

TGA head John Skerritt said there would be no upper age limit for the vaccine.

He said the British vaccine rollout had shown “very good results obtained with both of the major vaccines in older groups”.

Professor Skerritt did not provide specific guidance on the vaccination of pregnant women, but said women who had received jabs were being watched closely.

“There were a number of people who didn’t know they were pregnant or became pregnant during the trials, and there haven’t been reports of adverse outcomes,” he said.

He said those women and other frontline workers who had actively chosen to be vaccinated while pregnant were being “closely followed on a register”.

“Those babies are yet to be born and so forth, again, there’s no evidence of anything untoward such as miscarriage or illness during pregnancy,” Professor Skerritt said.

The TGA said the advice was for the AstraZeneca jab to be administered in two doses, 12 weeks apart.

If that is not possible, a minimum interval of four weeks between doses can be used.

Australia has secured 53.8 million doses of the AstraZeneca vaccine, 50 million of them to be made in Melbourne by medical giant CSL to guarantee future supply.

Victorian state authorities – who were providing an update on the latest lockdown as the news of the approval emerged – were among the first to welcome the announcement.

“That’s probably the most rigorous testing and approval process anywhere in the world,” Premier Daniel Andrews said.

“I think that should give every Victorian absolute confidence that they should get it. I’ll get it. Kath [his wife] will get it. The kids will get it. My mum will get it. Every Victorian should get this. It will change the way we live and it will save lives and you can’t get much more important than that.”

State chief health officer Brett Sutton said it was terrific news.

“Who wouldn’t be delighted at the prospect of another vaccine, especially one locally manufactured, that will deliver millions of doses to Australians?” he said.

“The mental health anguish of this pandemic has been extraordinary. It literally represents the beginning of the end of this pandemic as we roll out a vaccine so it is incredibly positive.”

The first shipment of Pfizer virus vaccines arrived in Sydney on Monday.

There had been concerns about whether Australia would receive its order after the European Union introduced new rules on exports of COVID-19 vaccines produced within the bloc, including Pfizer.

But last week the EU’s ambassador to Australia said the doses would be allowed to leave Europe.

The TGA said AstraZeneca had been shown to prevent COVID-19, the disease caused by the coronavirus, but it was not clear yet whether it prevented transmission or asymptomatic disease.

However, a recent study by Oxford University, which has not yet been peer-reviewed, found the AstraZeneca vaccine not only prevented severe disease, but appeared to cut transmission of the virus by about 67 per cent.

On Monday, Health Minister Greg Hunt said about a million doses a week would be made available from the end of March.

But the exact rollout date is still uncertain.

Unlike the Pfizer vaccine, which must be stored between -60 and -90 degrees, the AstraZeneca vaccine only needs to be stored at 4 degrees.

“It’s important to remember that approval of the AstraZeneca vaccine will really help with people getting vaccinated,” Professor Skerritt said.

“If you use half an AstraZeneca vial in a GP’s practice, it can go back in the fridge overnight and be used again the next day.

“You don’t have to throw it out.”

The Pfizer vaccine will be rolled out using multidose vials, which further adds to the logistical challenge of rolling it out.

The first 142,000 doses of the Pfizer vaccine landed in Australia on Monday, with vaccinations due to start on February 22.

-with agencies