Australians could soon be able to access a Covid vaccine booster shot, after the drugs regulator provisionally approved Pfizer third doses for those who are 18 and over.
The Therapeutic Goods Administration gave the manufacturer provisional approval on Wednesday, meaning Pfizer must continue clinical trials examining the efficacy of the booster shot, and to submit ongoing evidence from those trials for review by the regulator.
The decision follows the approval of a booster dose for severely immunocompromised people aged 12 years and over at least 28 days after the second dose. This group has been eligible to receive a booster dose of Pfizer since 11 October.
So how do you get a booster shot and what difference do they make to your protection against Covid?
When can I get my third booster dose?
The start of the rollout of booster shots for the general population could be only a couple of weeks away.
Now that the TGA has signed off (provisionally), the Australian Technical Advisory Group on Immunisation [Atagi] also needs to give its view. Atagi comprises independent medical and consumer experts who advise the government on how to make sure the rollout is equitable, evidence-based and safe.
The health minister, Greg Hunt, said on Wednesday he expected Atagi’s final advice wouldn’t be far away and the government hoped the booster program would begin by 8 November.
However, just like the vaccine rollout, some groups will have priority.
“We will commence aged care and disability as a priority,” Hunt said. This will begin “immediately” in Victoria, he said, which is still struggling with high case numbers. A consent process is being rolled out in aged care and disability facilities to fast track that, and the booster will then be administered by TLC Healthcare, which is helping Victorian aged care providers with the vaccine rollout. Atagi has already provided preliminary advice approving the booster for these groups.
The TGA said booster shots must be given at least six months after the first two vaccine doses. For now, the government’s priority is making sure as many people as possible receive their first two doses of a Covid vaccine, because even after six months, the two-doses still provides protection against severe illness and hospitalisation. However, overall protection against Covid and breakthrough infections wane over time.
A strong study from Israel published in the New England Journal of Medicine in October found that among 1,137,804 people 60 years or older, those who had received a booster shot at least five months earlier had “substantially lower” rates of Covid-19 and severe illness compared to those in the same age group who had received two shots.
What brand of vaccine will I get for my booster?
Currently, only Pfizer has been approved for use as a booster dose. While Australians must receive the same brand of vaccine for their first two doses other than in exceptional circumstances, the TGA says the booster Pfizer dose can be given no matter what brand of vaccine was given for the first two doses.
The government expects that Moderna will also apply to the TGA for the registration and approval of booster doses. It is similar to the Pfizer vaccine. The TGA has also received part of an application from Pfizer to have its vaccine for use in children between the ages of five and 11 approved.
The head of the TGA, Prof John Skerritt, said by 1 January, about 1.6 million people will be six months or more from their second vaccine dose and eligible for a booster. He said there is “more than enough” Pfizer supply to cover them.
Will I need another booster shot after the third dose?
The head of the molecular virology laboratory at the Peter Doherty Institute for Infection and Immunity at the University of Melbourne, Prof Damian Purcell, said it is too early to know.
“It’s going to need another six to eight months of monitoring the data internationally to see whether, again, the immunity diminishes,” Purcell said. “But there is some hope from animal studies that it’s going to provide a longer, more sustained boost. But we don’t know until enough people have had the third dose and we have been able to monitor them for more than six months.”
Skerritt agreed: “We’ll have to wait and see.”
“There are some vaccines [for other diseases] whereby three shots gives you almost lifelong protection,” he said. “No one knows about the duration of protection post this booster. The really good news is that a few months ago, we were worried we’d have to have quite different vaccines because of the emergence of variants. But even with the severity of Delta and how predominant Delta has been globally, we haven’t needed to change the vaccine or booster.”
How will I know when I am due for my third dose?
It is unclear whether state and territory run vaccination hubs are likely to send text messages and reminders about a third dose, as they currently do in some states for booking a second dose. Some GP clinics also send out text message reminders for second doses.
Email: sign up for our daily morning and afternoon email newsletters
App: download our free app and never miss the biggest stories
Social: follow us on YouTube, TikTok, Instagram, Facebook or Twitter
Podcast: listen to our daily episodes on Apple Podcasts, Spotify or search "Full Story" in your favourite app
This detail is likely to be worked out once Atagi releases its advice and priority groups for boosters are finalised.
It is unlikely to matter whether you receive the third dose from a GP or vaccination hub; currently, people can get their first two vaccine doses at different locations.
Will I need the third dose to be considered fully vaccinated?
Whether a third dose will be mandated will depend on employers, and rules in different jurisdictions.
On Sunday, the Victorian premier Daniel Andrews said participating in the states “vaccinated economy” in future may “be about the maintenance of your vaccination status” through a booster shot.
Hunt said at this stage a booster will not be mandatory for being able to travel overseas and return to Australia, or to be considered fully vaccinated by the federal government. But he said he encourages every Australian to get the booster once eligible.
Boosters will eventually be required to enter some other countries. Austria and Croatia have already put expiry dates on Covid vaccine certificates of 270 days, with a booster required for entry after that. Israel requires three doses before considering someone fully vaccinated. Other countries may follow.
