The spread of COVID-19 in Australia is no longer being controlled by vaccines as a result of low booster shot uptake rates and the emergence of more potent variants that can evade immunity. With the transmission-suppressing effect of vaccines falling, the current vaccination policies are ineffective in preventing community-wide transmission. The only aim of Australia’s vaccination strategy is to protect high-risk groups from severe outcomes resulting from COVID infection. While current government health advice recommends a fifth booster dose for healthy individuals aged 18 to 64, take-up rates for successive doses have declined. The benefits of booster shots for reducing transmission are minimal, and young, healthy, and double-vaccinated individuals face low risks from the virus even without a booster. It is difficult to identify the group most at risk of severe disease and death from COVID-19 at a population level. Professor Miles Davenport, the head of the infection analytics program at the Kirby Institute, believes that regularly boosting young, healthy individuals every six months may not be cost-effective in the long term.
Vaccines are no longer as effective at controlling the spread of COVID-19 in Australia due to low take-up rates for booster shots and the emergence of more potent variants that can evade immunity. According to federal government modelling, the transmission-suppressing effect of vaccination and prior infection has declined from 60% in Victoria in March 2022 to just 12% at present. Moreover, the current vaccination policies are no longer effective in preventing community-wide transmission, according to Associate Professor James Trauer, head of Monash University’s epidemiological modelling unit. Instead, vaccines are now used to protect high-risk groups from severe outcomes resulting from COVID infection rather than from the infection itself.
Current health advice from the government recommends that healthy Australians aged 18 to 64 “consider” a fifth booster dose, with the sole aim of preventing severe illness. However, take-up rates for every successive dose have fallen, with just 45.2% of eligible Australians receiving a fourth dose. Even individuals who have had COVID-19 and have recovered without experiencing any long-term symptoms, like John Connell, a 41-year-old school facilities manager, are unwilling to get additional boosters.
Federal government modelling uses Omicron-based data, which is even more immune evasive than the current variants, suggesting that the transmission-suppressing effect of vaccines may be lower than 12%. Professor Julie Leask, a leading vaccination researcher at the University of Sydney, believes that vaccination numbers will continue to decline unless something exceptional happens, such as the emergence of a dangerous new variant.
In summary, the declining take-up rates for booster shots and the emergence of more potent variants that can evade immunity mean that vaccines are no longer as effective at controlling the spread of COVID-19 in Australia. The current vaccination policies only aim to protect high-risk groups from severe outcomes resulting from COVID infection. However, with the transmission-suppressing effect of vaccines falling, experts predict that vaccination numbers will continue to decline unless exceptional circumstances arise.
The emergence of the Omicron variant and its offshoots has changed the vaccination landscape as these viruses have a greater ability to evade immunity, even from bivalent vaccines that target both the original strain and Omicron in one shot. Although evidence suggests that booster vaccinations can reduce the chances of transmitting the virus, the benefits are minimal. A study of California inmates in early 2022 revealed that unvaccinated prisoners had a 36% chance of passing on the virus, while vaccinated prisoners had a 28% chance. Boosting provided a small additional benefit.
Young, healthy, and double-vaccinated individuals face very low risks from the virus, even without a booster. For those who have received a booster, almost all the risk of death falls on people over 80 years old, according to new research.
Professor Miles Davenport, the head of the infection analytics program at the Kirby Institute, believes that it remains unclear whether regularly boosting young, healthy individuals every six months would be cost-effective in the long run. With infections now spreading unchecked throughout the community, our focus should be on ensuring that vulnerable individuals receive their boosters, especially those who have not been reinfected in the past six months.
According to Professor Julie Leask, a leading vaccination researcher at the University of Sydney, the most at-risk groups of severe disease and death from COVID-19 are those who require boosters, but it is difficult to identify them at a population level.
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