Online tool helps assess risks from COVID-19 and vaccination

Since Australia’s vaccine rollout commenced in February, GPs have been spending a significant amount of time discussing the risks and benefits of COVID-19 vaccination.
 
But with COVID likely to become further entrenched in the coming weeks and months as Australia further opens up, it is hoped a new online tool could help patients make an informed decision around vaccination.  
 
Launched on Monday by the Immunisation Coalition, the COVID-19 Risk Calculator (CoRiCal) allows people to assess their individual chance of contracting and dying from COVID-19 based on their age, gender, community transmission rates and vaccination status.
 
Melbourne GP Dr Andrew Baird, who is a co-lead researcher on the project, said it has been designed with GPs in mind and will support them with up-to-date data.
 
‘When patients present with apprehension or uncertainty about the risk of COVID-19 and the role of vaccination, it’s there as a tool to support them so that the GP and the patient can look at the screen together and work through the charts,’ he told newsGP.
 
‘The GP can demonstrate “Here is your risk of developing COVID-19 if the level of transmission is high and here is your risk of developing COVID-19 if you’re vaccinated”.’
 
As well as assessing the risks of COVID-19 infection, CoRiCal also helps GPs to calculate the risks of any rare vaccine adverse effects, such as thrombosis with thrombocytopenia syndrome (TTS) associated with AstraZeneca.
 
‘And it’s shown in context so that we can say, “Here are the risks for getting COVID-19 and here are the risks for getting adverse effects from the vaccines”,’ Dr Baird said.
 
‘It demonstrates the relative risks, showing that the risks [associated with] getting COVID-19 are much higher than the risk of getting any adverse effects from the vaccines themselves.’
 
Meanwhile, to help put the risks of both COVID-19 infection and vaccination into perspective, the tool also generates relatable risks, such as the chance of being struck by lightning or winning the lottery.
 
‘None of us are very good at understanding very low risks,’ Dr Baird said.
 
‘If we can just put it in some sort of context [to be] able to say, “The chances of getting blood clots from an AstraZeneca vaccine are around about the same risks as getting struck by lightning”, people think “Well, getting struck by lightning, that’s pretty rare”.
 
‘I think that’s a helpful communication.’
 
According to the tool, for an unvaccinated 65-year-old female patient in Victoria, where transmission would be considered high, the chance of contracting COVID-19 over six months is 32,000 per 1,000,000 and chance of dying once infected is 8100 per 1,000,000.
 
Meanwhile, the chance of getting a blood clot from a first dose of AstraZeneca is 16 per 1,000,000 and the chance of death is 0.8 per 1,000,000 – nearly half the reported the risk of being killed by an asteroid, which is 1.4 per 1,000,000. 
 
Though the tool has been designed to assist GPs and other clinicians, it is publicly available online, allowing people in the community to input their own information and explore various scenarios.
 
Dr Baird said patients may then take that information to their GP to become a starting point to discuss vaccination.
 
The CoRiCal project has been informed by a range of experts, including GPs, with the risk calculations based on a modelling framework developed by the University of Queensland’s Professor Colleen Lau and Dr Helen Mayfield, and Queensland University of Technology’s Professor Kerrie Mengersen.
 
Currently in its pilot stage, the tool only includes data on the risks and benefits of the AstraZeneca vaccine, with plans to continuously update it with the latest health and scientific advice, including on booster shots, ICU admission and long COVID.
 
Dr Baird said he anticipates the tool will be updated with data on Pfizer and Moderna in 2–4 weeks, including risk assessments on developing myocarditis and pericarditis.
 
While currently based on the Delta strain, the platform can also be updated should any new vaccines, such as Novavax, come onboard, as well as any new variants that could emerge.
 
‘So it’s a living tool, and will be continuously developed and updated according to needs and circumstances,’ Dr Baird said.
 
‘The hard work has been done already, getting the tool set up and the algorithms and the model working, so it’s relatively straightforward to put new data into the model.’
 
To further tailor the risk assessment, the longer-term plan is to include data on pre-existing medical conditions such as obesity and diabetes.
 
This will bring the tool in line with the University of Oxford’s QCOVID, which is used in the UK.
 
‘That is an excellent tool and, in fact, we had looked at [it] and had been doing some work with them early on in the development of CoRiCal,’ Dr Baird said.
 
‘The way the UK collect their data and use their data is remarkable. So we aspire to do what QCOVID is doing, but we just haven’t had data in that form so we can put that information together.’
 
Despite reports of vaccine hesitancy, Australian vaccination rates are on track to be some of the highest in the world, with 86.7% of those aged 16 and over having received at least one dose as of 25 October. 
 
At this stage of the rollout, however, Dr Baird said it is anticipated that overcoming any hesitancy will become increasingly more challenging for GPs as the unvaccinated are more likely to be the ‘hardcore vaccine hesitant individuals’.
 
That’s where he thinks the tool will come in useful.
 
‘Willingness to get vaccinated has driven the uptake and the acceleration of the program, but now things are starting to slow down a little bit,’ Dr Baird said.
 
‘So it is that little bit harder and, in those conversations, people are looking for a little bit more information and they want to know that it’s accurate and that it’s evidence based, which the tool is.’
 
Associate Professor John Litt, CoRiCal instigator from Flinders University and Immunisation Coalition Scientific Advisory Committee member, agrees.
 
‘An accurate, evidence-based tool that is transparent and unaligned with professional groups should help GPs in their task of facilitating COVID vaccination for their patients,’ he said.
 
Dr Baird believes it could even be key to getting Australia well beyond its 80% vaccination target.
 
‘It’s not the whole answer,’ he said. ‘But it’s certainly an important part of assisting GPs in their conversations with patients.’
 
The COVID-19 Risk Calculator (CoRiCal) can be accessed on the Immunisation Coalition’s website.
 
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