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- Data from the UK shows that a single shot of a COVID-19 vaccine drastically cut the rate of hospitalization.
- Figures from Scotland show the shot led to people being on average 84% less likely to be hospitalised.
- The news is the latest in a series of promising updates on the real-world effectiveness of vaccines.
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Both the Pfizer and the AstraZeneca COVID-19 vaccines were found to substantially reduce hospitalization from after a single jab, according to new data out of the UK.
The figures, published early Monday, are the first to measure the rate of hospitalization from a real-world vaccine rollout.
It is the latest in a series of promising updates from countries which have vaccinated significant proportions of their populations.
Monday’s data came from Scotland, one of the four nations of the UK. It analyzed the health records of 5.4 million people between December 8 and February 15.
Of those, more than 1.1 million received one dose of either the Pfizer/BioNTech or the Oxford/AstraZeneca vaccine, both of which are authorized for use in the UK.
The scientists found that those who received the vaccine were significantly less likely to be hospitalized than those who hadn't.
Looking at the protection overall, hospitalization from COVID-19 dropped by 84% four weeks after receiving a jab.
The UK decided to prioritize giving as many people as possible a single jab, even though the manufacturers recommend two for the fullest protection. As a result, relatively few in the UK have had a second dose.
Breaking down the data, one dose of the Pfizer vaccine cut hospitalizations by 85% four weeks after the first jab, and the AstraZeneca vaccine cut hospitalizations up to 94%.
The scientists also measured the effect of the vaccine every week after receiving the first dose. They found the vaccine had the strongest effect in the fourth week after inoculation.
Vaccine effect was highest on those aged 18-64. However, in that age bracket, only those who have been defined as clinically vulnerable would have received the vaccine.
Among those aged over 80 years, who are at the highest risk from COVID-19, the vaccine gave 81% reduction in hospitalization after four weeks.
This study was published as a pre-print, the next step will be for it to be reviewed by peers.
This is the first study looking at the effect of a vaccine on hospitalization for an entire nation, the scientists said.
Real-world data from Israel's rapid vaccine campaign has previously shown that the Pfizer vaccine cuts 94% of symptomatic cases after two doses of the vaccine, a separate measure of effectiveness.
Lead scientist Aziz Sheik from the University of Edinburgh, said that this evidence "given us great reasons to be optimistic for the future."