Expert commentary: Pfizer-BioNTech COVID-19 vaccine authorised in UK

On 2 December 2020 the UK’s independent regulator, the Medicines & Healthcare Products Regulatory Agency, authorised Pfizer-BioNTech’s COVID-19 vaccine for emergency supply in the UK.

CSIRO’s experts, Dr Rob Grenfell and Prof Trevor Drew, comment on the news.

Dr Rob Grenfell, CSIRO’s Health and Biosecurity Director

“Yesterday was a significant day in the global fight against the pandemic as the UK became the first country to authorise the Pfizer-BioNTech COVID-19 vaccine for emergency supply on the recommendation of its independent Medicines & Healthcare Products Regulatory Agency.”

“The Australian Government secured a supply deal for 10 million doses of the Pfizer-BioNTech vaccine in November, with the first doses expected to arrive in Australia early next year pending regulatory approval by the Therapeutic Goods Administration.”

“Emergency authorisation was granted by the UK regulator, an independent body which based its recommendation on analysis of the initial preclinical trials through to the phased human clinical trials. The results of Pfizer-BioNTech’s phase III clinical trials are expected to be published in a peer reviewed scientific journal in the coming months.”

“From a public health perspective, we hope to see as many vaccines as possible reach this stage and to pass regulatory approvals should they prove to be safe and effective. Not all vaccines have the same level of efficacy across different demographics or are easily transportable, so it is important to have options that work across the broader population.”

“As we wait for a vaccine to be rolled out in Australia, we must remain vigilant and continue with contact tracing, social distancing and practicing good hand hygiene.”

Professor Trevor Drew, Director, CSIRO’s Australian Centre for Disease Preparedness

“While this is good news, it is important to remember the fight against COVID-19 is far from over. Current vaccines confer protection against the COVID-19 disease, but immunised individuals who are subsequently exposed to the virus may still become infected and, though they may not show symptoms, might remain infectious for a short time. We all therefore need to continue to follow public health measures to limit to spread of the virus, even when a vaccine is deployed here in Australia.”

“The Pfizer-BioNTech vaccine is quite novel and works by inserting the genetic code for the spike protein of SARS-CoV-2 into the cytoplasm of the cell – if you imagine the cell as a fried egg, it’s the white bit. The cell then produces the spike protein using this code, which our immune system recognises as foreign and we develop immunity, which then protects us, should we subsequently become infected by the real virus.”

“The genetic code in the vaccine is in a form called ‘messenger RNA’ or mRNA. This is different to the DNA in our cells. which is found in the nucleus – the yellow bit of the fried egg model. The mRNA in the vaccine does not enter the nucleus and cannot incorporate itself into our genes – it only lasts for a few hours, while being used to make the spike protein and is then destroyed by our cells.”

“Pfizer and BioNTech’s primary efficacy analysis of the vaccine has shown it is 95 per cent effective against COVID-19. This is a very encouraging level of efficacy, considering most seasonal flu vaccines are around 60-70 per cent efficacious.”

“However, this particular vaccine needs to be stored at around -70°C and the logistics of maintaining this temperature through supply chains is a significant hurdle to overcome, before a widespread rollout of the vaccine can be implemented.”

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