Two-thirds of the population in England are insufficiently protected against the Delta coronavirus variant, exclusive data analysis by the Guardian can reveal.
Despite promising signs that the vaccine is working – including record low hospital admissions in relation to the number of cases – this lack of immunity is critical to the government’s decision to further ease restrictions.
Boris Johnson is considering a four-week delay to the last stage of lockdown reopening, which would see theatres and nightclubs open and large gatherings such as weddings allowed.
Two-thirds are still unprotected
While the vaccine rollout has been successful, two-thirds of the population in England are still not protected by vaccines against symptomatic infection from the Delta variant.
This is based on an analysis of who has been vaccinated, the number and type of doses they received, and the effectiveness of these vaccines against the Delta variant in the real world.
A single dose of any vaccine is only 33% effective against the Delta variant, according to Public Health England.
This means the risk of becoming ill is 33% lower among people who have had one dose of the vaccine compared with those who have not been vaccinated. So for every 100 unvaccinated people who ended up with symptomatic Covid, for instance, only 67 would have been expected to have fallen ill had they had all had one dose.
Two doses gives greater protection: AstraZeneca’s effectiveness is 60% after two doses, while Pfizer’s is 88% against the Delta variant.
Combining these effectiveness figures with our knowledge of who has received what vaccines, our analysis suggests an estimated 68 of every 100 people have no more protection against getting coronavirus symptoms, than they had before the vaccination programme started.
Paul Hunter, a professor in medicine at the University of East Anglia, said that while these figures showed the protection given against symptomatic Covid, the most important thing was severe disease.
“Hospitalisations per case have plummeted. Vaccination is stopping severe disease. We don’t know vaccine protectiveness against the Delta variant for severe disease, but vaccines do protect more against severe disease. To me, it’s severe disease that really matters.”
Cases remain low among older people
Despite the vaccine rollout not yet being complete, there are signs that the programme is working, with case rates among older people remaining low.
The recent rise in cases has been largely centred on people aged under 39, with particular concern over the spread in schools.
But this isn’t translating into a significant rise among older people – who are most likely to die from Covid-19 and now also those with the greatest level of vaccination coverage – which could mean that the vaccine rollout is shielding the most vulnerable from getting infected in this latest surge.
Breaking the link between cases and hospital admissions
The protection of older people is having a direct impact on Covid-19 hospital admissions and deaths.
Government figures show there were 753 hospital admissions in England in the week from 9 June. This is 5.4% of the number of cases recorded in the weekly period two weeks before this point.
This ratio has consistently stood below 6% since late March, for the first time in the pandemic. This compares with the start of the year when admissions were up at 10% of cases recorded two weeks before.
Experts confirmed that this indicates that the vaccine rollout is beginning to break the link between cases and severe illness. However, they caution that the Delta variant may disrupt this trend, with a noticeable stall in the drop in hospital admissions in recent weeks.
In a further sign that the vaccine rollout is working, England is also seeing a record low period for the proportion of cases that end in deaths three weeks later.
This proportion has remained below 0.5% – one in 200 cases – since the beginning of April, despite never being this level since the start of the pandemic.
Finally, the number of deaths as a proportion of hospital admissions one week earlier is also remaining very low.
The death rate had never been lower than 10% of the number of admissions one week earlier before April, but it has since remained consistently at or below this level.
Many areas are yet to see more than half their population vaccinated – leaving gaps in our protection
While the vaccine rollout is starting to drive down hospital admissions and deaths, there are still communities that lag far behind the average vaccination rate.
An analysis of England’s more than 6,000 middle super output areas (MSOAs) – small geographic units with an average population of 8,000 – reveals pockets with very low levels of protection in every region.
Across England as a whole, nearly 60% of the population have had a first dose of the vaccine. But in 993 areas – many of which are younger and more ethnically diverse inner-city neighbourhoods – less than half of residents had their first jab by 30 May.
These areas – located in cities such as Birmingham, Leeds and London – also suffer from higher levels of deprivation, meaning residents have a higher baseline risk of premature death and face significant barriers accessing local services.
George Batchelor, the director of the health data company Edge Health, said these less vaccinated populations could see spikes in cases even if the country were reaching herd immunity. However, he said the recent outbreak in Bolton – where cases are now falling again – showed that “vaccines, testing and communication can all work together to combat the virus”.
“This is good news as fundamentally the risk profile has changed”.
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