Should young people consider taking the AstraZeneca vaccine?

by Guy Suttner

On Monday, Australian Prime Minister Scott Morrison announced that those under-40 can now request an AstraZeneca vaccine from their GP. Guy argues that young Australians should examine the benefits of receiving this particular vaccine.

Note: This author of this article is not a medical professional and this is not medical advice. Please consult with a GP before making any decisions regarding your immunisation.   

Australia vaccination rollout has been sluggish, with 6.36% (1.63 million) of the population being fully vaccinated and 24.03% (6.17 million) having received at least one dose. Australia primarily sourced the Oxford-AstraZeneca (AZ) vaccine for the rollout. This was to be supplemented by two mRNA vaccines, from February 2021 the Pfizer-BioNTech vaccine, and from November 2021 the Moderna vaccine. While the slow rollout is caused by several factors, two issues appear key. Firstly, that the Australian Technical Advisory Group on Immunisation (ATAGI) has recommended that under-60s do not receive the AZ vaccine. Consequentially, vaccine hesitancy among the population has increased, as people are content to wait for the ‘superior’ mRNA vaccines.  

In response to June 2021 Sydney COVID outbreak, the Prime Minister seemed to imply in a recent press conference that a possible solution was for individual’s under-40 to receive the AZ vaccine. He did this by announcing a scheme to indemnify GPs against adverse side effects suffered by patients. This was followed by a backlash from some State Governments, most notably from the Queensland Chief Health Officer, Dr Jeanette Young, who stated that “she did not want to see any young person receive AstraZeneca”.  

This situation has created an incredible amount of confusion, so what is actually going on?  

What is the medical advice? 

The ATAGI position is that “for people under 60 years, Pfizer is the preferred over COVID-19 vaccine over AstraZeneca”. The reason for this is that younger individuals have a higher chance of suffering from a rare blood clotting issue known as thrombocytopenia syndrome (TTS). In every 100,000 first doses given to people under 50, 3.1 doses of TTS are estimated to occur, compared to a 2.7 in 100,000 chance for the 50-59 group, and 1.4 in 100,000 chance for the 60-69 group. However, the ATAGI believes that “AstraZeneca can be used in adults under 60 years when the benefits are likely to outweigh the risks and the consumer has informed [consent]”.  

The Therapeutic Goods Administration (TGA) has approved the AstraZeneca vaccine for all adults over the age of 18. The president of the RACGP has stated that whether under-40s receive the AstraZeneca vaccine is an individual decision for GPs and their patients.  

Accordingly, whether young people should get the AZ vaccine involves a calculation of whether the risk of TTS outweighs the benefits the vaccines provide.  

What is the risk? 

According to ATAGI, approximately 3.1 individuals out of every 100,000 under 40 who receive their first dose of the AZ vaccine will develop blood clotting issues. Data from the UK indicates that this risk massively decreases after the 2nd dose.  

TTS is a serious condition with an estimated 3% mortality rate. This indicates the risk of dying from the AZ vaccine for those under-40 is approximately 1 in 2 million. 2 people in Australia have already died due to the AZ vaccine, both aged 48 and 52 years old respectively. It is worth noting that some individuals may be more susceptible to adverse side-effects as a result of pre-existing conditions. Please consult with a GP before making any significant medical decisions.  

In comparison, the case fatality rate for COVID-19 among 20 to 40-year old’s is approximately 0.3%, which translates to 6000 deaths per every 2 million people. You are around 6000 times more likely to die from COVID than you are from the AZ vaccine. This stands in addition to the risks of developing chronic health issues from Long COVID. Other activities that young people regularly engage in carry even higher risks, from driving to extreme sports.   

What is the benefit? 

The AZ vaccine is effective. Against the original strain of COVID-19, the efficacy of the AZ vaccine at preventing infection was found to be approximately 81.3%. Against the Delta strain currently circulating around Australia, that was reduced to approximately 60% (30% after only one does). Importantly, the AZ vaccine is 92% effective against hospitalisation and even more so against death, meaning it is a crucial tool in protecting the elderly and immuno-compromised.  

However, the benefit of immunity against COVID depends upon how much transmission there is in the community. ATAGI’s decision to only recommend AstraZeneca to those 50 and above, and subsequently 60 and above, was premised on the threat of COVID-19 being extremely low. According to their own modelling, if the risk of COVID-19 was to increase, then it would begin to outweigh the risk posed by TTS to young people. For example, assume there was another outbreak equivalent to the second wave in Victoria (275 infections among 100,000 people over a 16-week period) and that those in the 30-39 age group were vaccinated. While this level of vaccination would cause 1.6 cases of TTS, it would also prevent 10.7 hospitalisations from COVID. In that scenario, the benefits massively outweigh the harms.  

It is also worth noting that while the Pfizer vaccine seems to have less harmful side effects, it has still been linked to issues such as myocarditis. No vaccine is risk-free, they all need to be balanced against the probable benefit.  

The bigger picture 

One key issue with this paradigm adopted by ATAGI is that it does not factor the costs of continuing Australia’s zero-COVID strategy. Australia has achieved some of the best outcomes in regard to COVID-19 of the entire world, but only as the result of significant concessions. States (except NSW) have introduced lockdowns every time there has been community transmission. Restrictions have been placed on venues, funerals, weddings, and other important parts of life. State borders have suddenly closed in response to cases, tearing families apart. Many overseas Australians cannot return home, and many Australians cannot leave to see family. These costs are real and deep for many.  

Importantly, this policy framework will continue until every Australian adult has had the opportunity to receive a vaccine. By withholding our supplies of AstraZeneca from young, willing Australians, we delay herd immunity and accordingly freedom from onerous COVID restrictions.  

Our zero-COVID strategy impacts the health advice. While borders remain closed the risk of contracting COVID-19 remains low, which means that ATAGI is likely to be conservative in who it recommends receives AZ. If this occurs, less people are vaccinated, vaccine hesitancy increases, and our borders stay closed for even longer. We are stuck in a positive feedback loop that is making our ascent out of this pandemic incredibly slow.  

The irony here is that in a world where borders opened tomorrow, and the risk of dying from COVID-19 significantly increased, then we might see a situation where Dr Young is advocate for every young person to receive AstraZeneca. Our hard borders have protected Australia, but they are now also locking us in.  

Getting vaccinated 

The Government estimates that every person under 60 will have the chance to get vaccinated with an mRNA vaccine by October, which would mean their 2nd dose would be administered in November. Considering the unreliability of previous predictions and the existing slow trend of vaccinations, this does not appear credible. For young Australians seeking an alternative, they can call GPs and ask for the AZ vaccine. As long as they are aware of the risks, they can then receive their first dose now and their second by September, at the earliest. AZ vaccines have been added to the government’s eligibility tracker.  

If you are prepared to take on the rare risks of TTS, getting fully vaccinated with AstraZeneca will likely provide you with strong protection against COVID-19 months before you are eligible for an mRNA vaccine. It will also help bring forward Australia’s vaccination effort so that our lives can finally return to normal.