COVID-19: Delta variant increases risk of hospitalization, but vaccination protection remains high, study suggests | News from the UK
The risk of being hospitalized with the Delta (Indian) variant of the coronavirus is about twice that of the Alpha (Kent) strain, but two doses of vaccine still offer strong protection against it, new data suggests.
The level of protection against the Indian variant of COVID-19 may be lower than the Kent variant, early research published in The Lancet suggests.
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The analyzed data from 5.4 million people in Scotland shows that the Delta variant is the dominant form of the virus in the country today.
During the period under study – April 1 to June 6 – there were 19,543 cases of COVID in the community, with 377 hospital admissions where a specific variant was confirmed.
In a total of 7,723 cases and 134 hospital admissions, the delta variant was found, which is believed to be about 60% more transmissible than the alpha variant.
The researchers said those with underlying conditions were at higher risk of being hospitalized, as was the case with previous variants.
They found that while vaccines reduced the risk of hospitalization, strong effects against the Delta variant weren’t seen until 28 days after the first vaccination.
The Pfizer BioNTech vaccination was found to offer 79% protection against infection from the Delta variant, compared to 92% against the Alpha strain. In community cases, at least two weeks after the second dose.
The Oxford-AstraZeneca-Jab offered 60% protection against infections in the Delta variant – compared to 73% in the Alpha variant.
According to experts, the lower vaccination effect could be due to the fact that it takes longer to develop immunity after the Oxford vaccination.
The study was funded by the Medical Research Council, UK Research and the Innovation Industrial Strategy Challenge Fund and Health Data Research UK (HDR UK) – and supported by the Scottish Government.
Professor Aziz Sheikh, Director of the Usher Institute at the University of Edinburgh and Head of Studies of EAVE II, said: “Within a few weeks, the Delta variant has become the dominant strain of SARS-CoV-2 in Scotland.
“Unfortunately, it is associated with an increased risk of hospitalization due to COVID-19.
“While may not be as effective as against other variants, two doses of the Pfizer / BioNTech and Oxford / AstraZeneca vaccines still offer significant protection against the risk of infection and hospitalization.
“So it is really important that when people are offered second doses, take them, both to protect themselves and to reduce transmission in households and communities.”
Prof. Sheikh said at a press conference that a delay in the lockdown will be eased will later be announced by Boris Johnson, would allow more people to receive the increased protection that two jabs offer.
He said, “If there is a delay, I think that will give us an opportunity to expand coverage, which is incredibly important for those who are currently only on one dose.
“There will be an opportunity to increase the population with two doses, and then we want a period of time when people can actually maximize their immune response.
“I think any kind of lengthening of the window of time before the lockdowns are fully completed will help as it will help us control the community broadcast.
“So overall, I would be very supportive of any delays that could be announced.”
Dr. Jim McMenamin, COVID-19 National Incident Director for Public Health Scotland, said, “These results encourage early on that two doses of Pfizer / BioNTech or Oxford / AstraZeneca vaccines reduce the risk of infection against both the Alpha and the new Delta Significantly reduce the variant.
“They also show that the vaccines with the new Delta variant offer protection against the risk of hospitalization.
“While no vaccine can provide 100% protection, they offer the best protection against COVID-19 and it remains important to receive both doses when they are offered.”
The researchers say their work needs to be repeated in other countries and settings to increase confidence in their early results.
They also say that the data on the effectiveness of the vaccines should be interpreted with caution due to the observational nature of the study and a direct comparison between the two vaccines is not possible.