Explainer

The fourth COVID-19 vaccine dose may not be enough to curb new Omicron sub-variants. Here's why

Millions more people are now eligible for a fourth COVID-19 vaccine, but Australia's vaccines advisory body says the extra jab won't be enough in itself to stop the new Omicron wave.

A nurse administers a vaccine in the arm of a woman wearing a mask and glasses

More Australians are now eligible to receive a fourth COVID-19 vaccine in a bid to curb an increased spread of the BA.4 and BA.5 Omicron sub-variants across the country. Source: Getty / Lisa Maree Williams

Key Points
  • More Australians will be eligible to receive a COVID-19 vaccine dose in an attempt to grapple with a new wave of Omicron sub-variants.
  • But ATAGI has warned that the fourth jab won't be enough to curb a new wave of sub-variants of the Omicron virus
Australians aged 30 and above will be eligible to in an attempt to grapple with a new wave of Omicron sub-variants during winter.

The federal government has accepted the advice from the Australian Technical Advisory Group on Immunisation (ATAGI) that people aged between 50 to 64 are "highly recommended" to receive the fourth so-called "winter dose".

The expanded rollout will begin on Monday, and it's estimated more than seven million Australians will be able to get their fourth jab, in line with a staggering increase of COVID-19 infections and hospitalisations in recent weeks.
This is due to the increased transmission of that have been described as a cause for concern for the country's under-pressure health system in the middle of winter.

But ATAGI has warned that even its recommendation for more Australians to receive their fourth COVID-19 vaccine "is expected to be limited" in its effect on curbing the virus outbreak.

According to experts, here is why, and what can be done at an individual and community level to manage the new wave to minimise severe illness and death across the country.

'Transmission is king'

Nancy Baxter, Head of the Melbourne School of Population and Global Health at the University of Melbourne, says it's critical to understand one thing when it comes to the newly dominant sub-variants, BA.4 and BA.5 of Omicron.

"Transmission is king," she told SBS News.
"[The sub-variants] are worse actors in terms of being more able to get around our immune system and they're more transmissible, and they're easier to catch, even if you've had a vaccine or had COVID," she said.

Professor Baxter said that the BA.4 and BA.5 were "successful variants" in averting the immune system, and have remained highly transmissible.

"The way it's designed itself to get around immunity and to increase its ability to do that as it's changed has really made it have much more of a stickiness. It's stuck around," she said.

How did we get here?

Professor Baxter said there is a "triple whammy" factor of reasons that have led to a resurgence of COVID-19 infections.

Australians entered winter at a time when Omicron's sub-variants have been transmitting at a highly infectious rate. This is all while fewer public health restrictions were enforced, and when many people's vaccine efficacy or their immunity from having received COVID-19 has waned.

"We're creating an environment for the virus that it can it can spread, we're less protected and we have a more infectious sub-variant," she said.
It also comes as Australia's third dose take-up rate has plummeted, with only 70.6 per cent of people having received the first booster that has been described by health authorities as critical at controlling hospitalisation and severe illness due to COVID-19.

That's been described as "sub-optimal" by professor of immunology at Perth's Murdoch University, Cassandra Berry.

"If you're not healthy, you can't run a business and you can't create wealth. If you can't save lives, there is no life worth living," she said.

"We do need some sort of shake-up and to be on high alert now."

How can we maximise the vaccine's effectiveness?

ATAGI has made it clear that getting the fourth jab plays a "limited yet important role" in managing the pandemic. It has continued to urge Australians to exercise more stringent public health measures, adjacent to receiving the COVID-19 vaccine.

This includes the return to wearing face masks, social distancing and regular hand-washing and sanitising, as well as antiviral treatment for those aged over 50.

"Gone are the days where we used to do elbow bumps, but that social restriction is still very important to keep infected people away from healthy people," Professor Berry said.

Some critics have called on the government to bring back compulsory mask-wearing indoors, but .

"The message is 'take responsibility, make your own choice'," he told the ABC on Friday.
"We're deep into the third year of the pandemic and we need to make sure that people feel they're able to take control of their own circumstances."

Professor Baxter said rather than re-enforcing a mask mandate, she hoped that Australians would take the initiative in choosing to wear a face mask first — and that politicians would lead by example.

"I wish that people look around them and would say, 'I need to wear masks to protect myself and my community', and we wouldn't have to mandate them because Australians would do what's right," she said.

"If we need a mask mandate to make our political leaders wear a mask, then I guess we need a mask mandate."

Will we need COVID-19 boosters forever?

While millions of Australians are now preparing to roll their sleeves up for their fourth dose, Professor Berry said Australians must face the reality that COVID-19 vaccines may likely remain with us for the rest of our lives.

"The best shield of protection is to get updated vaccines and I think boosters are going to be here forever for COVID, just like we have for influenza," she said.
Both Professors Baxter and Berry flagged that the current vaccine that is being rolled out around the world is aimed at targeting Alpha, one of the first few variants of COVID-19.

The Therapeutic Goods Administration has on Wednesday given that is expected to successfully manage these BA.4 and BA.5 sub-variants.

If and until the next variant comes along, though, it's expected that booster vaccines are here to stay.

"In order for us to have the fewest people possible die, fewest people possible in hospital and the fewest people possible having long-term disability because of COVID, we're just going to have to continue with relatively exceptional measures for the next perhaps two years," Professor Baxter said.

Why can't people aged 30 and younger get the fourth dose?

For now, ATAGI has held back from advising those aged under 30 to receive the second booster, unless they have a medical condition that increases the risk of severe COVID-19.

However, Professor Berry said it would be ideal for people in their 20s to receive additional protection from catching and, subsequently, transmitting the virus.

According to the government's health data, as of July 2022, Australians aged between 20 to 29 are the highest group of people who tested positive for COVID-19 due to their increased mobility and interactions with others.

"Even though they are not seen to be hospitalised and die at the same rates as the older, more vulnerable people, they are still contracting, and able to be reinfected with these Omicron variants and spread the virus in the community," she said.

Meanwhile, those aged between 30 and 50 are eligible to get their fourth COVID-19 jab, but ATAGI said the benefit for Australians in this age group "is less certain".

Share
7 min read
Published 8 July 2022 3:35pm
Updated 8 July 2022 5:18pm
By Rayane Tamer
Source: SBS News


Share this with family and friends