The delta variant of the corona virus is considered to be particularly contagious. And apparently also increases the risk of hospitalization, as a British study shows. However, the data must be interpreted with caution.
According to a study, the risk of hospitalization is around twice as high as with the alpha variant if you are infected with the delta variant of the coronavirus. Researchers from the University of Cambridge and the Public Health England authority evaluated more than 40,000 corona cases in England between the end of March and the end of May 2021. The results published in the specialist journal “” relate above all to the risk for unvaccinated people. The data do not allow any conclusions to be drawn for fully vaccinated persons.
So far, studies have mainly shown the higher transferability of the delta variant; there were hardly any reliable statements about the risk of severe courses. The scientists now used the results of tens of thousands of positive tests that had been assigned to delta or alpha by means of genetic analyzes. Almost 9,000 went back to Delta, around 35,000 to Alpha. In relation to this, the researchers looked at the number of hospital admissions.
Higher risk with Delta
After adjusting the data for factors such as age and demographics, which usually increase the risk of developing serious illness, they found that infected with Delta had a mean 2.26-fold higher risk of hospitalization within two weeks of the test fixed. The risk of having to go to an emergency room or be hospitalized within 14 days was therefore 1.45 times higher with Delta than with Alpha.
Of the more than 40,000 cases examined in the study, only 1.8 percent were fully vaccinated, which the researchers interpret as further confirmation that the vaccines are very effective. 74 percent of the infected people considered were unvaccinated, 24 percent only partially vaccinated, i.e. with only one vaccination dose. Because of the limited amount of data available for this, the researchers are unable to make any statements as to whether there is a higher risk of serious illness in vaccinated persons as well.
Call for vaccination
“Our analysis shows that without vaccinations, delta outbreaks pose a significantly greater burden on the health system than an alpha epidemic,” said one of the study authors, Anne Presanis of Cambridge University. “Getting fully vaccinated is critical to reducing your risk of symptomatic infection and lowering your risk of developing severe delta infection and being hospitalized.”
The authors cite the weaknesses of their study that they did not have any data on the previous illnesses of their patients. It is also possible that the rules for hospital admissions have changed during the trial period. The researchers at least tried to minimize these factors in their calculations as much as possible.
The delta variant, which was initially proven in India, is now the dominant one in many countries such as Great Britain and Germany. Experts anticipate that it will largely displace other variants worldwide – unless an even more contagious one spreads. Delta was first detected in England in March.
