What's next phase of COVID-19 vaccination program?
Covid-19 update
It is with no surprise that multiple questions occupy the minds of Australians as Covid-19 continues to dominate our lives and the best way to counter this pandemic.
Among the questions is whether a second booster shot will be required. To date, the Federal Government’s Department of Health has confirmed that 11.2 million Australians have received a booster.
A UNSW study proffers the following:
- For those who received their third dose back in November, the question is, what next?
- Is waning immunity going to be an issue for those who received the booster more than three months ago?
- Will there be a fourth booster on the horizon for Australians?
- Where are we at with variant-specific vaccinations and ‘universal’ vaccinations?
A spokesperson for the Health Department said they are monitoring evidence, but did not commit to additional booster shots.
“To date, more than 53.8 million COVID-19 vaccinations have been administered across Australia and over 11.2 million Australians have received a COVID-19 booster.
“The Australian Technical Advisory Group on Immunisation (ATAGI) continues to monitor evidence emerging from medical research on the effectiveness of the COVID-19 vaccines both locally and internationally. ATAGI will update its advice and recommendations accordingly.
“Advice from ATAGI, including consideration of evidence surrounding booster doses for the COVID-19 vaccine, is regularly published on the Department of Health website, at www.health.gov.au ,” a spokesperson said in a statement to Newsport.
Next phase
In a report titled “What will be the next phase of the COVID-19 vaccination program in Australia?”, Dr Deborah Burnett, Conjoint Senior Lecturer at UNSW’s St Vincent's Clinical School, said data from multiple sources is now emerging that there are two factors at play necessitating the need for booster vaccinations against COVID-19.
“The first is, there is a large body of emerging evidence that although vaccination induces a robust protective antibody response against COVID-19, antibody response wanes over time, decreasing 20-fold from its peak within nine months.
“The second factor at play is because the strains we are now facing are so different from the strain used to formulate the original vaccine, the vaccines themselves are less effective at preventing infection from new variants.
“While six to 12 months post-second vaccine most people still have antibodies that would protect them against infection with the original strain of SARS-CoV-2 – the virus that causes COVID-19 – only a minority of people have antibodies that would protect them against the infection with the Omicron variant,” said Dr Burnett.
But questions remain regarding boosters.
Dr Burnett said a third booster increases the protective levels of antibodies so that most people are then protected against infection with the Omicron variant, however, it is unclear how long this protection lasts.
“Early evidence from the UK suggests that even following a third vaccine booster, protection against Omicron infection falls 30% from its peak levels within three months.
Fourth booster
“For this reason, many countries around the world are considering or even implementing a fourth vaccine booster program.
“It is currently unknown how much a fourth booster will actually further increase protection against infection and disease but given that some countries such as Israel have already started the rollout of the fourth booster program, we expect this data to be available shortly. This data will help influence whether Australia adopts a similar strategy,” said Dr Burnett.
Dr Burnett said the good news is, although breakthrough infections may occur in the vaccinated, there appears to be a greater ability of current vaccines to protect against serious disease caused by variants.
“However, protection against hospitalisation appears to fall over time, with the UK data showing a third booster provides 92% protection against hospitalisation against the Omicron strain, but this falls to 83% within three months.
“As such, there is a strong logic to initially prioritising those individuals who have a higher chance of severe disease following infection with the virus."
Several groups, including Dr Burnett’s team, in collaboration with Prof. Chris Goodnow and Prof. Daniel Christ at the Garvan Institute and several other teams across UNSW and Australia, are working on strategies to generate a ‘universal’ COVID-19 vaccine that would be resistant to future strains of COVID-19.
Lessen the effects
Dr Burnett said instead of rolling out a vaccine after a variant emerges to lessen the effects of that variant, ‘universal’ vaccines have the potential to provide for a much better population-level control of COVID-19, as they could potentially prevent future outbreaks from occurring.
But Dr Burnett warns as long as Australia doesn’t have its own sovereign vaccine production capacities, it will continue to suffer from instabilities in vaccine supply and is unlikely to be at the front of the queue when a new vaccine is rolled out.
“As such, onshore production of mRNA vaccines is critical for Australia’s future. Australia is already initiating arrangements with Moderna for the industrial production of mRNA vaccines in Australia from 2024.
“In addition, hopefully, the NSW RNA Bioscience Alliance will continue to grow to establish a pathway allowing for the development of Australian designed vaccines to be translated into real-world products.”
Full report: