But Jamie Triccas, a senior professor of immunology at the University of Sydney, said waiting for data on the effectiveness of vaccines targeting new Omicron subvariants could be problematic.
“I would think that if there seems to be a delay in approving these new variant enhancers, or if there will be problems with access, so how much can they produce in a short period of time, I think we” to look closely at the possibility of scheduling a fourth dose just to maintain the community’s level of protection, ”Triccas said.
“If for most people it’s been six months since the last dose and high levels of Omicron are circulating and the onset of BA.4 and BA.5 is also increasing, I would say [the need for a fourth dose] it should be a conversation we should take seriously now. “
Professor James Triccas, a vaccine researcher, in a laboratory at the University of Sydney. Credit: Nick Moir
Epidemiologist Nancy Baxter, head of the University of Melbourne’s School of Population and Global Health, said a specific Omicron boost would be very beneficial. But it would be detrimental to wait more than three months for that, he said.
“The problem would be if we plan to have a normal Omicron boost in six months … in six months, who knows what will happen? But if we’re planning to have an Omicron boost in the next three months, this makes a lot of sense.
“This will be a relentless winter. So if they have an effective Omicron-specific vaccine, it might make sense to launch it in three months.
Baxter said we were likely to be in an “Omicron phase” for a while, but noted that committing to a booster injection targeting specific COVID-19 variant strains posed challenges when the virus mutated continuously.
The head of the epidemiological modeling unit at Monash University, James Trauer, said the high mortality rate in Australia for COVID-19 meant there would be no delay in approving the fourth booster injections. He said improving the rate of third and fourth vaccinations should be a matter of priority. More than 300 Australians are losing their lives due to COVID-19 every week.
“We have pretty high mortality rates, they’re higher than a lot of Western European countries right now,” Trauer said. “I think people lost a little bit of protection when they were vaccinated.”
Associate Professor James Trauer.
A spokesman for the Department of Health and Human Services said Moderna had filed a provisional registration application for a bivalent vaccine against COVID-19 that would target the original, ancestral strain and the Omicron BA.1 strain.
“As the assessment progresses, the TGA will continue to seek information from Modern Australia, until all required information is provided and a regulatory decision can be made.”
Butler said Australia “did not work well” in taking the third and fourth doses. Nearly 6 million Australians who are eligible for a third dose have not yet received it. Sixty-four percent of eligible seniors care residents have received their fourth dose.
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