Israeli Study Suggests British COVID Strain Linked to Rise in Serious Cases

New research by Israeli HMO Clalit shows that among 50,000 Israeli coronavirus patients, 70 percent deteriorated into serious condition than among patients before the U.K. strain was detected in Israel

Ido Efrati
Ido Efrati
Medical workers, seen through a window of an observation room, wear personal protective equipment (PPE) as they work inside an underground ward treating patients with the coronavirus disease at Sheba Medical Center.
Medical workers, seen through a window of an observation room, wear personal protective equipment (PPE) as they work inside an underground ward treating patients with the coronavirus disease at Sheba Credit: RONEN ZVULUN / REUTERS
Ido Efrati
Ido Efrati

The so-called U.K. variant of coronavirus has contributed significantly to the rise in the number of serious cases of the disease, according to newly published research by the Clalit Health Maintenance Organization.

The study, conducted among some 50,000 non-vaccinated people who contracted the coronavirus in January and February 2021, shows a rise of 70 percent patients that became seriously ill compared to data on 60,000 people infected in previous months.

This suggests that the U.K. strain, B.1.1.7, has properties that differentiate it from the “original” COVID-19. So far, the most prominent difference is that it is more infectious. But it also appears that the illness it causes is much more violent than the original strain.

Clalit’s research corresponds to reports from doctors in coronavirus and intensive care wards around Israel, as reported recently by Haaretz. Doctors have also reported that coronavirus patients are now younger than before, and in many cases more severely ill than in the first and second outbreaks. Some doctors say that not only are the symptoms more severe and the patients younger and without pre-existing medical conditions, but deterioration sets in much more quickly than before.

Many hospitals throughout Israel have also reported in recent weeks that the condition of patients now hospitalized with coronavirus is much more complex. Among the severely ill patients, 44 are in very serious condition and are attached to heart-lung (ECMO) machines - which is a very high number compared to previous peaks.

The U.K. variant apparently arrived in Israel in December, and within a few weeks it proliferated in confirmed samples. Health Ministry data shows the strain is present in more than 90 percent of people who tested positive for the virus. Moreover, in January and February the vaccination drive took off, but the number of seriously ill patients has hardly declined.

The Clalit Research Institute followed non-vaccinated patients for 14 days from the time they were infected. The control group consisted of some 60,000 coronavirus patients during the period of October 1 to December 19 2020 (before the vaccination drive started and before the U.K. variant was identified in Israel). During that earlier period, the rate of deterioration to serious condition in 14 days was similar to past rates: 1 percent of patients age 30–50, 3.7 percent of patients age 50–60 and 14.5 percent of patients over 60.

The second group of patients the study followed numbered approximately 50,000 people who contracted the virus between January 17 and February 7, 2021, and were not vaccinated before they were diagnosed as positive. During this time, according to Health Ministry assessments, the U.K. variant was responsible for about 80 percent of new infections. The percentage of decline into serious condition within 14 days of diagnosis in the various age groups was 1.3 percent in patients age 30–50, 5.5 percent of patients age 50–60 and 19 percent of patients over 60.

“Our data provide a possible explanation why in the first weeks of this year no sharp decline was seen, as would have been expected, in the daily number of newly seriously ill patients, despite the growing numbers of vaccinated people and the great efficacy of the vaccinations as found in a large study by Clalit published this morning in the New England Journal of Medicine,” said Prof. Ran Balicer, director of the Clalit Research Institute and head of Clalit’s Health Policy Planning Department.

A elderly woman receives her second coronavirus shot at an assisted living facility, in Netanya, last month.Credit: RONEN ZVULUN / REUTERS

“According to the results, some of the general decline in the seriously ill patients of all ages due to vaccination was seen later and was limited in extent due to the sharp parallel rise in the seriously ill among infected, non-vaccinated patients of all age groups – a rise of 70 percent in relation to the period up to one month ago,” Balicer wrote.

According to Balicer, the Clalit study shows that since the beginning of 2021, the risk of serious illness has increased considerably among the non-vaccinated population, leading to the conclusion that and “the British strain (B.1.1.7) is not only more infectious – but also more dangerous,” Balicer wrote, adding that these results correspond to finding from Britain. If not for the lockdown and the vaccination drive, according to Balicer, “we would now be seeing a significantly greater number of seriously ill patients flooding the hospitals,” and that the lockdown and the vaccination drive have “made it possible in the meantime to contain the effect” of the U.K. variant.

“We find it fitting to publish these findings before scientific publication sand among colleagues to warn the public of the need to be cautious during the Purim holiday,” Balicer wrote. “We came out of lockdown into a new and unfamiliar reality of a more violent and infectious strain. Even those who have been vaccinated, and certainly those who have not yet done it – this is the time to act moderately and carefully and follow the Health Ministry’s directives. And of course, this is the time for those who have not yet been vaccinated to do it now,” he wrote.

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