Yes, there’s confusion about ATAGI’s AstraZeneca advice. But it’s in an extremely difficult position


Daniel Pockett/AAP

Hassan Vally, La Trobe UniversityOne can totally understand the frustration around where the AstraZeneca vaccine fits in our vaccine rollout in Australia.

At a time when we’re grappling with so much uncertainty, we need unambiguous information from the federal government about who should have this vaccine.

Instead, it feels very much like we’re swirling in a murky sea of information that is confusing and, at times, seems to be contradictory.




Read more:
Morrison government orders Pfizer ‘boosters’, while hoping new ATAGI advice will warm people to AstraZeneca


The confusion is compounded by the changing advice from ATAGI. ATAGI, the Australian Technical Advisory Group on Immunisation, is the group of vaccine experts which advises the government.

There is no doubt that for many people, some of its language has been difficult to make sense of, including the use of vague terms like “preferred”. As in, the Pfizer vaccine is the “preferred vaccine” for those under 60 years of age.

How exactly this should be interpreted by someone trying to make the important decision about whether to get the vaccine is unclear, and raises more questions than it answers.

The public commentary from a number of political leaders, including the prime minister, that ATAGI has been too conservative and too risk averse hasn’t helped either, with the implication ATAGI cannot be fully trusted to provide sensible advice.

The reality is, ATAGI is in an extremely difficult position and is grappling with competing concerns, considerable uncertainty, and a constantly changing landscape.

What is ATAGI’s role?

ATAGI can only give general advice to the government for the whole population.

Its task is to think about the whole population as if it were merged into a single person, or in the case of AstraZeneca, a series of people of different age ranges. It then has to formulate advice based on population-based averages of the benefits and risks of getting the AstraZeneca vaccine, which has a number of limitations.

It’s important to understand context plays a key role in formulating this advice to the government. The risk of the blood clotting and bleeding condition, called thrombosis with thrombocytopenia, from the AstraZeneca vaccine is slightly higher for younger people.

This is only part of what’s driven the advice for Pfizer to be the preferred vaccine for those under 60.

In fact, the risk of dying from this condition is incredibly rare whatever your age.




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What has been the bigger driver of the advice is the fact you’re less likely to develop severe disease from COVID if you’re younger, which means the corresponding benefits of vaccination are much lower if you take a narrow view of the benefits of the vaccine being solely the prevention of severe disease.

How did ATAGI draw its conclusions on AstraZeneca?

ATAGI initially said Pfizer was the preferred vaccine for under-50s in April, and then changed this to under-60s in June.

There are several assumptions in ATAGI’s advice which need to be understood.

Firstly, it calculated the risks and benefits of AstraZeneca across three scenarios — low, medium and high exposure risk. ATAGI has presented its advice assuming a low amount COVID circulating in the community, which has been the case until Sydney’s latest outbreak.

A low amount of COVID in the community means there’s a low chance of severe COVID, which is even smaller for younger people. This means there’s less of a benefit of being vaccinated for younger people, which is what has driven the advice for the Pfizer vaccine to be preferred for younger people.

However, the problem with this low prevalence assumption is we’re vaccinating to protect us not just right now, but also against the future risk of COVID, and future lockdowns, like the situation we’re seeing in Sydney now.

Once you’re in this situation, even if ATAGI changes its recommendations in response to more COVID circulating, which it did on Saturday, in some sense the horse has already bolted.

Another assumption implicit in ATAGI’s advice that it prefers under-60s get Pfizer, is that Pfizer is available and you have the option to get it now.

However, given the limited supply of Pfizer vaccine, the decision to hold off on the AstraZeneca vaccine is not one to get Pfizer, it is one to hold off on getting vaccinated at all. This leaves you exposed and vulnerable to COVID. This is an important distinction to make, which of course will change as we get more Pfizer vaccine.

Another major limitation in the ATAGI advice is the panel, in dealing with population-level data, takes a very narrow view of the benefits of vaccination: the prevention of severe disease.

It doesn’t take into account other benefits that may be relevant to many people. It doesn’t take into account the prevention of long COVID; the benefits of being vaccinated allowing travel and other freedoms; and, most glaringly, the importance many people place on getting vaccinated to protect their loved ones and the community.

These may weigh heavily on individuals but aren’t taken into account when you look at the risk-benefit calculation from a narrow perspective.

So what’s the bottom line on AstraZeneca?

We must remember the AstraZeneca vaccine is a fantastic vaccine.

It’s safe and effective, and two doses offer almost complete protection against severe disease and death from COVID, including the Delta variant.

It does carry a small risk of the blood clotting and bleeding condition, but this risk is incredibly small. COVID is much more of a threat to your health than the vaccine, as we are seeing in NSW right now.

If you’re under 60 years of age, the decision to have the AstraZeneca vaccine is one only you can make. But if you do make it, you should understand the benefits go beyond just preventing severe disease.The Conversation

Hassan Vally, Associate Professor, La Trobe University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Morrison government orders Pfizer ‘boosters’, while hoping new ATAGI advice will warm people to AstraZeneca


Michelle Grattan, University of CanberraWhile still struggling with a current shortage of Pfizer, the Morrison government announced it has secured 85 million doses of that vaccine for future “booster” shots.

This will be made up of 60 million doses in 2022, and 25 million doses in 2023. Delivery will start in the first quarter of next year.

Scott Morrison said on Sunday this was “prudent future proofing”, although there is still not definitive advice on when boosters will be needed.

Meanwhile the Australian Technical Advisory Group on Immunisation (ATAGI) has liberalised its advice on AstraZeneca.

It said in a statement on Saturday all people aged 18 and over in greater Sydney, including those under 60, “should strongly consider getting vaccinated with any available vaccine including COVID-19 Vaccine AstraZeneca”.

This was on the basis of the increasing risk of COVID and “ongoing constraints” of Pfizer, the advice said.

Last week Scott Morrison said the government was constantly appealing to ATAGI to review its advice on AZ according to the balance of risk. Many people have shied away from AZ, supplies of which are plentiful, after ATAGI’s caution about it for younger people because of rare blood clots.

Asked about some general practioners being reluctant to give AZ to people under 40, Morrison said he certainly hoped GPs “would be very mindful of the ATAGI advice”.

ATAGI is presently considering whether children between 12 and 15 years old should be vaccinated against COVID, with the government expecting advice in mid-August.

As the crisis continues in Sydney, on Sunday NSW reported 141 new locally acquired cases and two deaths, including a woman in her 30s. This followed Saturday’s report of 163 new cases in the previous 24 hours.

Victoria on Sunday reported 11 new local cases, and is on track to end its lockdown soon, as is South Australia.

Morrison again stressed the lockdown was the primary weapon in fighting the Sydney outbreak.

“There’s not an easy way to bring these cases down. And it’s the lockdown that does that work. The vaccines can provide some assistance, but they are not going to end this lockdown. What’s going to end this lockdown is it being effective.”

But NSW Premier Gladys Berejiklian, who tried unsuccessfully to get the vaccination program refocused on south west Sydney, the centre of the outbreak, has a different emphasis. “Please know that what will get us through this outbreak is a combination of our restrictions, but also of more people being vaccinated”.

Morrison has refused to alter the focus, saying this would “interrupt the rhythm of the national vaccine program”.

The federal government has found 50,000 extra Pfizer doses for NSW. Asked where these came from, Morrison said: “There are small variations in supply and delivery, which from time to time may ensure that there’s tens of thousands of doses that might be free at any given time.”

Morrison condemned Saturday’s Sydney anti-lockdown demonstration attended by thousands of people, which saw violence, dozens of people charged, and more being pursued where they can be identified.

He said it was not just selfish. “It was also self-defeating. It achieves no purpose. It will not end the lockdown sooner, it will only risk the lockdowns running further,” he said.

Asked about Queensland Nationals MP George Christensen, who attended a rally in Mackay, Morrison said: “As for other parts of the country that aren’t in lockdown, well, there is such a thing as free speech, and I’m not about to be imposing those sorts of restrictions on people’s free speech”.

Christensen said on Facebook, “Civil disobedience eventually becomes the only response to laws that restrict freedom. This is what we’ve seen in Melbourne today.”

Pressed on this, Morrison said: “The comments I made before related to an event that took place in Queensland where there are no lockdowns”.

The Prime Minister told the Liberal National Party state council in a virtual address on Sunday: “After a difficult start, the vaccine program is now making up lost ground, and quickly”.The Conversation

Michelle Grattan, Professorial Fellow, University of Canberra

This article is republished from The Conversation under a Creative Commons license. Read the original article.