Researchers show single dose of vaccines substantially cuts risk of hospital admission for Covid-19
Boris Johnson’s scheduled plans to unveil a route out of lockdown have been given a boost by data from Scotland’s vaccination programme that suggest both currently approved Covid-19 vaccines reduce the risk of hospitalisation, even after a single dose.
The prime minister is presenting plans to Parliament this afternoon that will detail an exit strategy for the current lockdown in England, likely including the reopening of educational establishments, including universities.
The Scottish study, which is yet to be peer reviewed, shows that four weeks after a single dose of either the Pfizer/BioNTech or Oxford/AstraZeneca vaccine, the risk of hospital admission due to Covid-19 is substantially reduced across all age groups.
Led by Eleftheria Vasileiou from the University of Edinburgh, the study found that, 28-34 days after the first dose, the BioNTech vaccine delivered 85 per cent efficacy against Covid-19 illness requiring hospitalisation. The figure was higher for the Oxford vaccine, at 94 per cent.
Researchers have expressed optimism over the results while cautioning that this was an observational study with a short follow-up period, so it should be interpreted with caution.
Stephen Evans, professor of pharmacoepidemiology at the London School of Hygiene and Tropical Medicine, said “it is clear that these are definitely encouraging results”. But he added, “it will be important that euphoria, especially from political sources that do not understand the uncertainty in the numerical values, does not cause premature decisions to be made”.
The prime minister’s strategy for gradually reopening the economy is expected to begin from 8 March, when the top four priority groups for vaccination will be three weeks into their first jab—the time it takes individuals to reach a reasonable level of protective immunity.
But it is still unclear how long vaccines protect people, and to what extent variants will become resistant to them, said Lawrence Young, professor of molecular oncology at Warwick Medical School.
“There remain a number of significant unknowns,” he warns.