Modelling that delayed lockdown lifting was flawed, admits scientist

Modelling that helped persuade the Government to delay the June 21 reopening was overly pessimistic and the lockdown lifting should "possibly" have gone ahead on time, a government adviser has admitted.

Dr Mike Tildesley, an epidemiologist from Warwick University, said Britain had been in a "much better situation than we thought" when his group released models suggesting third wave deaths could hit 72,000.

In an interview with the Unherd website, Dr Tildesley admitted the modelling had underestimated vaccine effectiveness and misjudged how cautious the public would be after earlier restrictions were lifted. 

Shortly after the modelling was released, Telegraph analysis showed that modellers had assumed AstraZeneca vaccine efficacy as low as 77 per cent after two doses, even though real-world Public Health England (PHE) data had already shown it was 92 per cent. 

Likewise, Pfizer effectiveness was modelled between 84 and 95 per cent, although PHE estimated it was 96 per cent.

How modelled data underestimated the effect of vaccines

Warwick models forecast more between 500 and 600 hospital admissions a day by now, while the country is in fact seeing around 250. 

Asked whether release day could have gone ahead if the right data had been included in the models, Dr Tildesley  said: "In hindsight, possibly."

The scientist, who is a member of the Government’s SPI-M (Scientific Pandemic Influenza Group on Modelling) added: "We’re in a position that the vaccine efficacy is a lot more effective, but this is the caveat here, the delay also enabled us to vaccinate a lot more people with a slightly higher level of restrictions in place.

"These models are only as good as the data that goes in. I work as an infectious disease modeller and I’ve always said that models should only form part of the decision-making process – you need health experts, economists, social scientists and a huge range of expertise."

How many more could we vaccinated with the delay to June 21?

Models put forward by Warwick, Imperial College and the London School of Hygiene and Tropical Medicine persuaded Boris Johnson to push back the lockdown lifting. Under the worst scenarios, they predicted 203,824 deaths by next June.

But Dr Tildesley said only a "shallow" third virus wave was now likely, adding that it was crucial life got back to normal on July 19. 

"It’s very much not going to be the situation we saw in October or January because of the fantastic progress with the vaccines," he said. "I’m cautiously optimistic given where we are. If you look at cases, they are going up in a really concerning way –  however, we haven’t yet seen that translate into a significant rise in hospital admissions and deaths.

"I am pretty hopeful that July 19 should proceed as planned and we won’t see a big rise in hospitalisations beyond that. We may see something of a rise. I think there will be a wave, but not anything like the same scale we saw in January."

The scientist also called on the Government to stop publishing death data for Covid because numbers were so small.

"We don’t say how many deaths there are from cancer or road accidents, or all these other things, and actually we’re at a stage where the number of deaths are in the 10s – significantly lower than deaths from other causes," he said.

"I don’t think it’s helpful in terms of enabling us to get back to normality."

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