Over the past couple of days, as understaffed hospitals struggle to keep their floors clean of excrement, and army troops are being deployed to drive ambulances, New South Wales’ top doctor has been pleading with the public to get a booster shot.
“I can’t stress enough the urgency of getting boosters,” she said.
It’s not news that a booster, or third COVID-19 jab (either Moderna or Pfizer) has been made necessary by the highly infectious, vaccine-resistant Omicron variant.
What’s new is good evidence that booster shots offer much greater protection against symptomatic disease, serious disease and death.
Public health policy is betting the farm on boosters dampening the Omicron crisis.
Millions more Australians on Wednesday became immediately eligible for COVID booster shots after changes in NSW, Victoria and South Australia.
These states reduced the interval between second and third COVID-19 jabs from four months to three on Wednesday.
More than five million people will be able to get a third shot at state-run vaccination hubs.
Victorian Premier Daniel Andrews has said that having a third shot may be necessary for people to be certified as fully vaccinated.
But will it make a difference?
Yes, a big difference.
British researchers, analysing data from the ongoing COV-Boost trial, found that for people who have received two jabs of the AstraZeneca vaccine, a Pfizer booster is 89.6 per cent effective at preventing symptomatic disease, compared to double vaccination.
A Moderna booster is 95.3 per cent effective.
For those who had Pfizer doses first, the relative effectiveness of the Pfizer booster is 82.8 per cent and Moderna 90.9 per cent compared to double vaccination.
This means that, with a booster shot, you may test positive for the virus, but in many cases you won’t show signs of illness.
The authors conclude: “This study provides real-world evidence of significant increased protection from the booster vaccine dose against mild and severe disease irrespective of the primary course.”
Great news for older people
Boosters appear to keep more older people out of hospital.
According to figures from the UK Health Security Agency, about three months after they received the third jab, protection against hospitalisation among those aged 65 and over remains about 90 per cent.
With just two vaccine doses, protection against severe disease drops to about 70 per cent after three months and to 50 per cent after six months.
With a booster dose, “the duration of protection against severe disease remains high, protection against mild symptomatic infection is more short-lived and drops to around 30 per cent by about three months”.
Risk of death greatly reduced
Two large studies, conducted in Israel and published in the New England Journal of Medicine, found a significant lift in protection against serious disease and death among people who have received a booster shot.
One study looked at data from more than 840 000 vaccinated people aged 50 years or older, 90 per cent of whom received a booster shot.
The death rate was 0.16 per 100,000 persons per day in the booster group compared with 2.98 per 100,000 persons per day in the group that had only received two jabs.
The second study involved almost 4.7 million vaccinated individuals aged 16 years or older.
Across age groups, “COVID-19 cases and severe illness were substantially lower among those who received a booster, as were deaths among those aged 60 years or older who were boosted”.
The Journal of the American Medical Association noted that: “Together, the findings indicated that COVID-19 boosters have a relative effectiveness of 90 per cent to 95 per cent against severe disease or death.”
In the New England Journal of Medicine, editorialist Dr Minal K. Patel, of the US Centers for Disease Control and Prevention’s COVID-19 Response International Task Force, noted that the studies “provide much-needed evidence of the effectiveness of the booster dose”.
To book a booster shot at a pharmacy, go here.
For the Australian government vaccine clinic finder, go here.