A few months ago the biggest question about covid-19 vaccines was whether any of them would work. Then, happily, we all found out that they would and calculated their efficacy based on clinical trial results. Today, we have 'real world' data.
Apples-to-apples comparisons are now possible, based on millions of people who got different vaccines in the same country at the same time. And recent data from Britain, which has given either Pfizer’s or AstraZeneca’s jabs to 20m people, paint a different picture from the trial results. Three studies show that single doses of the two jabs are similarly effective, reports The Economist.
The latest paper, a preprint for the Lancet published on 3 March, found that one dose of either jab is 80% protective against hospitalisation in people aged at least 80, starting 14 days after vaccination. Another study, in Scotland, included younger age groups and also found the two jabs had similar potency against hospitalisation.
For a virus seeking new hosts, this is bad news - which will only get worse. Few people in Britain have received second doses. However, Israel has almost finished a two-dose mass-vaccination programme using the Pfizer vaccine. According to the latest data from Israel, two doses are about 90% protective against any form of covid-19, including asymptomatic infection.
If the AstraZeneca vaccine also matches Pfizer’s efficacy, which now appears likely, it could play a leading role in ending the pandemic - so long as people do not reject it based on ill-founded swipes from the likes of Mr Macron, the French president.