When Australians will need Covid-19 booster vaccines

Booster doses of the Covid-19 vaccine may be needed by Australians who are already vaccinated, even before the rest of the population gets their first dose.

Booster doses of the Covid-19 vaccine may be needed by Australians vaccinated earlier this year, even before the rest of the population gets their first dose.

Already Russia and Israel are providing booster doses and the UK, Germany and France are planning to give vulnerable people a top-up shot of vaccine in September.

It comes as new research from Moderna and Novavax shows even the original version of their vaccines work as an effective booster against the Delta variant of the virus.

European countries and the US began vaccinating their population late last year so their booster shots are being delivered around nine months after the initial jabs were given.

Scott Morrison was the first Australian to get vaccinated in February and this suggests he may need a top up by the end of this year before other Australians have even had their first dose.

The effectiveness of Covid vaccines wanes over time. Picture: NCA Newswire /Gaye Gerard

Australia has booster doses of Moderna and Pfizer on order with delivery due later next year. We could also use the Novavax vaccine, which we have also ordered, as a booster.

“Given the timing that it seems likely we will get our supply, we are hopeful that most people would have already had the opportunity to get their first round of vaccines, and so that does mean that it (Novavax) would likely be a vaccine that would be positioned to provide boosting to people,” said University of Queensland’s Professor Paul Griffin who has conducted clinical trials on the Novavax vaccine.

Booster doses specific to the Delta strain are under rapid development.

However, new research suggests even half a dose of the Moderna’s original mRNA vaccine given as a booster will provide a 42-fold increase in protection against the delta variant of Covid.

A vial of Pfizer and BioNTech's Covid-19 vaccine. Picture: AFP

The Novavax vaccine can also act as a booster providing a six-fold increase in protection against the delta variant, new research released by the company overnight shows.

Research by Pfizer, which tracked vaccinated people over a six-month period, found the efficacy of Covid vaccines waned over time.

Efficacy of the Pfizer vaccine was highest at 96.2 per cent in the two months after a second shot, and declined gradually to 83.7 per cent by the four-month mark.

From then on there was a 6 per cent decline in vaccine efficacy every two months.

Evidence is mounting that even the fully vaccinated can contract the Delta strain of the virus.

However, those people do not get severe illness and are rarely hospitalised and the vaccines are fully protective against death from the virus.

The US Centre for Disease Control has found, if infected, they still carry as much virus in the nose and throat as unvaccinated people and can still spread the virus.

Australian National University infectious diseases expert Professor Peter Collignon said there is no real world evidence yet that fully vaccinated people need boosters.

“We only have test tube data and data in my view that is not enough to justify everybody in a country getting a third dose so far,” he said.

“The real test will be what happens in England, Canada, Europe, US over their coming winter. “If we see a whole lot of people who are vaccinated, losing percentage of protection against death and serious disease, then that’s sign that we need to do it.”

The World Health Organisation this week called for a ban on booster shots until at least poorer nation were vaccinated.