Covid-19: the Delta variant increases the risk of hospitalization, according to a British study
According to a British study, the Delta variant seriously increases the risk of hospitalization (illustrative image).
AP - Lewis Joly
Text by: RFI Follow
4 min
People infected with the Delta variant are twice as likely to be hospitalized for Covid-19 than those infected with the Alpha variant, concludes a British study published on Saturday.
Advertising
Read more
The Delta variant, first identified in India, was already known to be around 40% to 60% more transmissible than the Alpha variant, which had emerged in the UK in late 2020. But little information was yet available on its severity, although preliminary data from Scotland and Singapore already suggested an increased risk of hospitalization and severe forms of Covid-19 with this variant.
A risk multiplied by 2.26
The study published Saturday, August 28 in the journal
The Lancet Infectious Diseases
establishes that people infected with the Delta variant are more likely to end up in a hospital bed than those infected with the Delta variant. The authors of the study analyzed data from more than 43,000 Covid cases recorded in England between March 29 and May 23, when the Delta variant began to spread across the Channel.
The proportion of cases linked to the Alpha variant (confirmed by sequencing) was 80% on average over the entire period (99.8% in the first week, declining to 34.8% in the last), while 20% were due to the Delta variant. Three-quarters of them (74%) were not vaccinated and a quarter (24%) had received only one dose, with fully vaccinated people accounting for only 1.8% of infections.
Among this cohort, 2.3% of Delta positive cases were hospitalized within two weeks of their positive test, compared to 2.2% of Alpha variant cases.
A difference that may seem small.
But by restating the data to take into account factors known to vary the risk of severe form of Covid (age, ethnic group, vaccination status), the researchers calculate that the risk of being admitted to the hospital is multiplied by 2, 26 with the Delta variant compared to the Alpha variant.
The patients affected by the Delta variant were notably younger, with a median age of 29 years, against 31 years for the Alpha variant.
The importance of a complete vaccination
Given the low proportion of people vaccinated in the study population, "
the results of this study tell us above all about the risk of admission to hospital for those who are not vaccinated or partially vaccinated
", underlines Anne Presanis, co. -author of the study.
"
Our analysis shows that if we did not have the vaccination, an epidemic due to the Delta variant would place a greater burden on the health system than if it were caused by the Alpha variant
", underlined Anne Presanis, statistician at the Cambridge University.
Several studies have shown that the vaccines retain a very high efficacy against severe forms of Covid linked to the Delta variant, provided they have a complete vaccination.
Their effect is limited after a single dose.
"
While this variant now represents more than 98% of Covid-19 cases in the United Kingdom, it is vital that those who have not received two doses do so as quickly as possible
", underlines Gavin Dabrera, co-author researcher and epidemiologist at Public Health England.
(
with
AFP
)
Newsletter
Receive all international news directly in your mailbox
I subscribe
Follow all the international news by downloading the RFI application
google-play-badge_FR
Coronavirus
Health and medicine