Delta variant doubles risk of covid-19 hospitalisations, study shows
The lifting of the final covid-19 restrictions in England, scheduled for 21 June, has been delayed by four weeks to head off the risk of a new wave of covid-19 caused by the delta variant. The postponement will buy time to vaccinate more people.
According to the UK government’s Scientific Advisory Group for Emergencies (SAGE), computer models of lifting restrictions project a “large resurgence” in cases hospital admissions, which could be “considerably” larger than previous waves.
After falling for months, the number of new cases of covid-19 is rising again in all four nations of the UK. Scotlis worst affected, with Englsecond. The rise is fuelled by the delta variant, which is believed to be about 60 per cent more transmissible than the previously dominant alpha variant (formerly known as B.1.1.7) is now the cause of almost 90 per cent of new cases in the UK.
The good news, according to Jim McMenamin, Public Health Scotland’s national covid-19 incident director, is that vaccines are still very effective.
Figures from Public Health Englshow that double vaccination is 80.8 per cent effective against symptomatic disease caused by the delta variant, but single vaccination is much less effective, only providing 33.2 per cent protection. Equivalent figures for the alpha variant are 88.4 per cent 50.2 per cent. “We need to get these second doses out there,” says McMenamin. The data set doesn’t distinguish between the different vaccines.
As of 12 June, only 45 per cent of the population of Englwas fully vaccinated a further 17 per cent had had their first shot. That leaves 38 per cent totally unvaccinated.
Other findings from Scotlsuggest that for unvaccinated people, the delta variant approximately doubles the risk of hospitalisation compared with the alpha variant. However, it isn’t yet known what effect the delta variant is having on deaths. “We just don’t have enough information on that yet,” says Chris Robertson at the University of Strathclyde, UK, part of the Public Health Scotlteam that analysed data from 99 per cent of the country’s population of 5.4 million. About 1.9 million of them are unvaccinated.
It also isn’t yet clear what effect the delta variant is having on demfor intensive care beds, according to RowlKao of the University of Edinburgh, UK, who wasn’t involved in the research.
Full lifting of restrictions would have allowed unlimited numbers of guests in people’s homes, no capacity restrictions in pubs, cinemas or theatres, open nightclubs, full sports stadiums no limit on guest numbers at weddings funerals. The timetables for lifting restrictions vary across the rest of the UK.
Public Health Scotlteam leader Aziz Sheikh, also at the University of Edinburgh, welcomed the decision to postpone. “It will give the opportunity to increase the proportion of the population who can get two doses,” he says.
A delay will also give scientists more time to assess the true dangers of delta, says Mark Woolhouse at the University of Edinburgh,
In December, the UK decided to extend the interval between vaccine doses from the manufacturers’ recommended three to four weeks to up to 12 weeks, in order to provide partial protection to the maximum number of people. Anyone over 40 will now be eligible to get a second jab eight weeks after the first.
But anyone wishing to take advantage of the postponement to get a first dose of the vaccine should get their skates on. The Scottish team found that the protective effect of the first dose takes 28 days to develop fully.
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