Only 32 people hospitalised with Covid after having vaccination
An article in the Telegraph has claimed that only 32 vaccinated people were hospitalised with Covid-19 in recent months. It also said that “of 74,405 Covid-19 cases admitted to hospitals between September and March, just 32 had received a vaccine at least three weeks before.”
This paints a misleading picture of what exactly has happened with vaccinated people getting hospitalised for Covid-19.
Researchers looked at a number of hospital admissions in the UK during the second wave, 74,405 to be exact, between September 2020 and March 2021. From 8 December 2020, the date the first people were vaccinated in the UK outside of trials, 42,788 were admitted. Of those, 1,802 had been vaccinated.
The vaccine doesn’t offer protection from Covid-19 immediately after having it. Regardless of the particular vaccine you get, immunity from just one dose is thought to peak between three and four weeks after the injection.
The researchers worked out how many of the 1,802 vaccinated hospitalised people had received the vaccine three or more weeks before. According to one of the researchers involved, Professor Calum Semple, who spoke to the Today programme, that number was 32.
But it’s not correct to look at that 32 as a proportion of the total 74,405 patients in the study (as the Telegraph did) to show how effective the vaccine seems to be at stopping hospitalisations for Covid. That’s because the 74,405 figure includes people who were hospitalised in the months before the vaccine roll-out even began, as well as those who had been vaccinated, but caught Covid-19 before the vaccine had a chance to build up immunity (three weeks after they got it).
Dividing 32 by 74,000 to get “one case per 2,300 patients”, as the Telegraph has done, is misleading. We could calculate a different figure: the percentage of theoretically fully immunised people who did end up in hospital with Covid. To do that we’d divide 32 by 1,802, which is 1.8%. That is still a pretty good sign that the vaccine is working.
The Telegraph also claimed that this showed the vaccines “offered protection far above the levels which had been anticipated”. It’s true that these findings show that the vaccine works and works well, but not beyond the realms of possibility considering other sources of data which used different methodologies.
The research described by the Telegraph wasn’t published in a journal and peer-reviewed as normal studies are—it is part of rapidly produced evidence by academics from multiple universities presented to SAGE, the government’s Scientific Advisory Group for Emergencies. It was presented to SAGE on 11 March.