“It’s clear that dexamethasone has had a big impact,” noted Horby. “A million is a big number … It’s an estimate that could well be lower than that or higher than that. We don’t know.”

The estimates touted by NHS England will be published on Tuesday, but they are understood to be based on a study published in the journal Nature Communications last month, which calculated that roughly 12,000 lives in the UK would have been saved between July and December 2020. This would translate into about 650,000 lives globally over the same period, the researchers wrote.