Fourth Covid jab rule change: Who gets it and why

More Australians are now eligible for a fourth Covid jab as cases surge across the country. Here is what you need to know and when you can get it.

All Australians over the age of 50 have been encouraged to get a fourth dose of a Covid-19 vaccine as an “even more infectious” subvariant of the omicron strain spurs a surge in cases.

Health Minister Mark Butler said the wave of new infections was putting pressure on the nation’s hospital systems, and urged older Australians to follow the latest advice from the immunisation expert panel regarding a fourth dose.

“States are reporting increased numbers of cases and increased numbers of people requiring admission to hospital because of Covid,” he said.

“There’s now 4000 hospital beds across the country filled by patients with Covid. That’s an increase of almost 1000 in just the last few weeks.”

Mr Butler said the number of people in intensive care units with Covid was up 40 per cent in the past week alone.

“Being up-to-date with your vaccines is crucial to protecting you against the risk of severe disease and particularly the risk of hospitalisation or worse,” he said.

The Minister for Health and Aged Care Mark Butler provides a COVID-19 vaccine update. Picture: AAP

Mr Butler confirmed Australia’s Technical Advisory Group on Immunisation (ATAGI) has recommended all Australians aged 50 and over take a fourth dose of a Covid vaccine.

Mr Butler said for people aged 30 to 49 a fourth dose was also available if they wanted it.

“The third element of the advice I have accepted today is that the interval between doses of vaccine or the internal between having been infected with Covid and getting your next dose of vaccine has been narrowed from four months down to three months,” he said.

The changes take effect from Monday, 11 July, to give primary care providers and pharmacies time to start making bookings.

Mr Butler said the BA4 and BA5 strains of the omicron variant have proven “very good at evading people’s immunity”.

“If you have immunity from vaccines or from having Covid, you’re still susceptible,” he said. “Just because you had Covid earlier in the year doesn’t mean you’re not at risk of getting it again with this third wave.”

Mr Butler said there were still more than five million Australians for whom it has been more than six months since their second dose, but had not yet had their third booster.

“I urge you to go out and get that third dose,” he said.

“It will provide you and people around you with more protection against this highly infectious subvariant BA4 and BA5.”

Mr Butler said more than 40 per cent of people aged over 65 had not taken up the opportunity to have a fourth dose, despite being eligible.

Who will be eligible for a fourth dose?

All Australians over the age of 50 are encouraged to get a fourth dose of a Covid-19 vaccine, while those over 30 are also able to access the fourth jab if they wish to.

Why do you need a fourth Covid booster vaccine?

The efficacy of Covid vaccines begins to wane after four months. A US study found the ability of a third vaccine dose to prevent infection was 87 per cent two months after receiving a third jab but dropped to 66 per cent four months later.

The ability of three vaccines to prevent severe disease and hospitalisation dropped from 91 per cent after two months to 78 per cent after four months the US study found.

Five million Australians have had only two doses of vaccine and they are very vulnerable right now.

The AstraZeneca vaccine was found by a US study to have no effect against Omicron so if you have only had two jabs and they were both AstraZeneca you are very vulnerable to infection right now.

If you only had two doses of an mRNA vaccine like Pfizer or Moderna you are also at rsk of infection. A US study found 25 weeks after your second dose the effectiveness of mRNA vaccines against infection from Omicron was just 14.9 per cent.

Five million Australians have not had their third jab, they should get it now.

If you think you are protected because you caught Covid before you are wrong.

There is growing concern that the new BA.4 and BA.5 Omicron variant sweeping Australia has learned how to evade not only protection from the vaccines but also immunity gained from catching the infection itself. Many people who had earlier versions of the virus are getting infected again.

How long will a fourth booster protect you?

Studies in Israel have found a fourth booster dose of the existing vaccines will lift your immunity against Covid infection by around 10-30 per cent. This extra protection begins to wane within 5-8 weeks. However, it should be enough to get you through the worst of the winter outbreak and help get you through to warmer weather where people are more likely to gather outside and less likely to spread infection.

Rules on who gets a fourth Covid booster dose are changing Picture: NCA NewsWire/Brenton Edwards

Why is it that younger people not recommended to get a booster?

One key reason experts are not advising younger people get a fourth jab is because the vaccines have rare side effects that can affect the hearts of younger people, particularly males. Younger people are much less likely to get severe infections from Covid or end up in hospital so the risks are thought to be greater than the benefit in this age group.

Why are experts changing the rules now?

Australia is in the midst of a severe outbreak of Covid with more than 33,000 new infections per day and more than 332 people a week dying from the virus, so any extra protection that can keep people out of hospital is needed.

The high infection rate is putting enormous strain on the hospital system. Nearly 4000 people are in hospital with Covid and many more are hospitalised with influenza. Many health workers themselves are unable to work because they are infected with various viruses. We urgently need to ease pressure on the health system any way we can.

From next week more people will be eligible for a fourth Covid jab.

There are new Omicron-specific vaccine boosters coming. Should I wait for them?

Both Pfizer and Moderna have produced new Omicron-specific vaccines. These are targeted at the original Omicron variant that swept the nation in December and January. Moderna’s Omicron vaccine lifts antibodies against this variant twelvefold. It also provides protection against the new BA.4 and BA.5 variants but this protection is much less.

These newer vaccines are likely to be approved by our medicines watchdog the Therapeutic Goods Administration (TGA) within days. However, they may not be in the country and available for use until August.

There is another month of rising infection rates before then so the best vaccine is the one you can get now. This is why experts will be urging Australians to get a fourth dose of the existing vaccines. There are 16 million doses of the existing vaccines sitting in warehouse shelves and available for use now.

Which vaccine should you get?

Experts theorise that mixing and matching vaccines could broaden your protection against the virus. So people who previously had a Pfizer booster may want to consider asking for a Moderna jab as their fourth dose and vice versa. But any vaccine will lift your protection and the best one is whichever vaccine you can get the fastest.

The Novavax and AstraZeneca vaccines are also available as booster shots but the TGA has said these are not preferred booster vaccines. However they can be used as a booster dose in people who have a had a serious adverse event following mRNA vaccines, e.g., a history of anaphylaxis or myocarditis attributed to an mRNA vaccine or in people who do not prefer an mRNA vaccine.

The Astra Zeneca vaccine has been found to offer virtually no protection against infection with the original Omicron variant.