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Media Release

Medal for paper that helped allay COVID-19 vaccine safety concerns

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Prof Colin Simpson

Professor Colin Simpson

A lead author behind one of the first papers in the world to confirm the safety of COVID-19 vaccines – including the Pfizer-BioNTech vaccine rolled out in New Zealand – has been awarded one of New Zealand’s top health research awards at the Royal Society Te Apārangi Research Honours Awards in Wellington tonight.

Epidemiologist Professor Colin Simpson of Victoria University of Wellington has received the Health Research Council (HRC) Liley Medal for the influential paper, published in Nature Medicine, that looked at the effectiveness and safety of the Pfizer-BioNTech and Oxford-AstraZeneca COVID-19 vaccines using data from Scotland1.

A key aim of the study was to determine if there was any association between these two COVID-19 vaccines – particularly the Oxford-AstraZeneca vaccine – and reported adverse blood clotting and vascular events.

The study that the paper was based on, and which Professor Simpson co-led, analysed data from 2.53 million (57.5%) Scotland residents who had received first doses of one of these COVID-19 vaccines between December 2020 and April 2021. During this time, Scotland was experiencing waves of both the alpha and delta variant of COVID-19 and was in the early stages of a national vaccine rollout, while New Zealand had very few cases of COVID-19 in the community.  

Professor Simpson and his UK-based team members found no link between the Pfizer-BioNTech vaccine and any of the adverse effects under examination.

The first dose of Oxford-AstraZeneca was found to be associated with small increased risks of some adverse events such as idiopathic thrombocytopenic purpura – a blood disorder characterised by an abnormal decrease in the number of platelets in the blood. This risk was similar to other common vaccines and the likelihood of these events was much higher in those who contracted COVID-19. The paper recommended that given these small increased risks with the Oxford-AstraZeneca vaccine, alternative vaccines for individuals at low COVID-19 risk might be warranted when supply allowed.

HRC Chief Executive Professor Sunny Collings says the incredible speed at which this study was completed – it took just five to six weeks to do the research – was paramount as some countries in Europe had already halted or limited use of the Oxford-AstraZeneca vaccine and there were concerns that safety fears would drive vaccine hesitancy among the public.

“The results of this study came at a critical point in worldwide vaccination programmes. The ability of Professor Simpson and his team to provide rapid reassurance of the safety and effectiveness of these COVID-19 vaccines was globally impactful and likely saved many lives by encouraging a high vaccine uptake,” says Professor Collings.

In New Zealand, addressing these safety concerns was particularly important as vaccine hesitancy is greater in Māori communities, who are a high-risk population.

“It was imperative that we had teams of independent scientists looking into the effectiveness and safety of these vaccines in the real world, beyond clinical trials. If this study had showed up lots of red flags, New Zealand may have turned towards another vaccine. Reassuringly, it showed that New Zealand identified the right vaccine,” says Professor Collings.

Professor Simpson says the reason he and his team were able to carry out this research and get the findings published so swiftly all came down to preparation, with the original study conceived in 2012 off the back of the H1N1 swine flu pandemic.

“Dame Sally Davies, who was the UK Chief Medical Officer at the time, felt we could have been better prepared for the swine flu pandemic, so a portfolio of research projects was created for a future pandemic, of which our study was one. The projects were then ‘put into hibernation’ until such time as they were needed. It wasn’t until the beginning of 2020, when the world first became aware of the seriousness of COVID-19, that I received an email saying, ‘prepare the project for activation’,” says Professor Simpson.

He says this study shows the importance of having data teams ready and prepared for a future pandemic.

“We have rich data sources in New Zealand, so it’s important that we tap into those sources and make sure that we have the teams in place who can generate the best information as quickly as possible to ensure the right policy decisions are made.”

In August this year, Professor Simpson and his team published a follow up study in Nature Communications and The Lancet looking at the effectiveness and safety of the Pfizer-BioNTech and Oxford-AstraZeneca vaccines after two doses and the results were very similar to just one dose. He is currently working on a Ministry of Health grant to explore the data needs for Māori communities during a pandemic and the effectiveness of the Pfizer-BioNTech vaccine during the COVID-19 Omicron wave in New Zealand.

Professor Simpson is the second recipient of the HRC’s Liley Medal this year. Professor Valery Feigin was also presented with a 2022 HRC Liley Medal at the Royal Society Te Apārangi’s Research Honours awards in Hamilton earlier this month for his paper on the global disease burden of stroke.

1Simpson, C.R., Shi, T., Vasileiou, E. et al. First-dose ChAdOx1 and BNT162b2 COVID-19 vaccines and thrombocytopenic, thromboembolic and hemorrhagic events in Scotland. Nat Med 27, 1290–1297 (2021).