All Australians may one day be infected with Covid-19 if immunity levels within the community are not maintained at high enough levels, experts say.
All Australians may eventually be infected with Covid-19 if immunity through vaccinations is not maintained at high enough levels, research shows.
More than 80 per cent of Australians aged 16 years and over have now been fully vaccinated against Covid but a much higher rate will be required to keep the virus under control.
Burnet Institute deputy director Margaret Hellard told the Sydney Morning Herald and The Age that Australia may be able to achieve protection equivalent to herd immunity if vaccination levels are well over 90 per cent, people get boosters when needed and new variants that don’t respond to vaccines emerge.
“But if those scenarios don’t play out, then it may be true that we’ll all eventually get infected,” she said.
Prof Hellard emphasised there was a lot of uncertainty about the future.
“This time last year we didn’t know there was a Delta variant coming in 2021,” she said.
“And in March 2020, if someone said we’d have vaccines by 2021 that were as good as they are, I would have said you’re being overly optimistic.”
Anyone who has been vaccinated would likely only get a mild version of the disease as effectiveness against hospitalisation among those who were double dosed with Pfizer remained high — at 93 per cent even after eight months.
However, research published in the The Lancet found protection against being infected by the Delta variant did fall, from 93 per cent at one month after vaccination, to 53 per cent after four months.
The results have led to many countries recommending booster shots but it’s unclear how often they will be necessary.
Last month Prime Minister Scott Morrison announced that Australians would be able to get a third vaccine dose, six months after their second jab but it’s unclear if further shots will be necessary.
Therapeutic Goods Administration (TGA) head Professor John Skerritt told reporters that “unfortunately the answer is we’ll have to wait and see”.
Meanwhile, experts have warned that Australia and other high income countries should not be prioritising booster shots while much of the world was not on track to be fully vaccinated by the end of 2022.
The Shot of Hope report, co-authored by an expert advisory group of researchers, analysts, and leaders from organisations including the Burnet Institute, noted that some countries would not reach the 70 per cent vaccination target until after 2030.
“The longer we allow developing countries to lag in terms of vaccination rates, the more time we give the virus to mutate and spread,” End Covid For All spokesman Reverend Tim Costello said.
The report noted a survey of 77 epidemiologists from 28 countries found two-thirds believed it would take less than a year before Covid-19 mutated to the point where the majority of vaccines were rendered ineffective if authorities did not act fast enough.
“Speed is of the essence,” the report states. “If we vaccinate the world faster, the likelihood of mutations drops.
“It is within our power to limit the chance of the next mutation from being so deadly and disruptive.”
Australia’s fast vaccination rate in states like Victoria and New South Wales has surprised authorities and led to the early lifting of restrictions.
However, some restrictions may need to remain in place to maintain suppression of the coronavirus, with one expert warning they may needed to be tightened ahead of Christmas if case numbers are too high.