Clalit’s study: The British strain is more dangerous

The Clalit Research Institute, headed by Prof. Ran Blitzer, presented today (Thursday) an important study on the effect of the British corona mutation in Israel. Data show that among the 50,000 insured of the fund who became infected in Corona (and were not vaccinated before) during January-February 2021, there was a 70% increase in the risk of serious illness. This is probably due to the spread of the British strain.

The study examined the rate of deterioration to severe morbidity in unvaccinated patients for 14 days from the date of their infection.

The follow-up included a comparison group of about 60,000 infected in Corona between 1 October and 19 December 2020 (before the start of the vaccination campaign and before the identification of the British mutation). During this period, the rate of deterioration to severe disease within 14 days among those infected was similar to previous rates – 1.0% in those aged 50-30, 3.7% in those aged 60-40 and 14.5% in those aged 60+.

The second group numbered about 50,000 people who became infected in Corona between January 17 and February 7 – and were not vaccinated. During this period, according to estimates by the Ministry of Health, the strain reached a rate of about 80% of new infections. During this period, a significantly higher rate of deterioration to a serious illness was indeed observed within 14 days of diagnosis: 1.3% at the age of 50-30, 5.5% at the age of 60-50 and 19% at the age of 60+.

Corona Commissioner Prof. Nachman Ash: “British mutation causes more serious illness” // Photo: Magen Israel headquarters

Taking into account all the risk factors and background of the infected, it was found that among the unvaccinated, infection in the period after 17 January (which was characterized by the spread of the British strain in the country) involved a statistically significant 70% increase in the average risk (for all ages). .

In examining the periodic change in the risk of developing a serious illness between different age groups, a relatively more significant increase was obtained the younger the age. While in the 60+ there was a 61% increase in the risk of developing a serious illness between the periods, in the 60-50s there was an increase of 93% and in the 50-30s an increase of 113% (in the younger ones the sample was too small to reach a conclusion).

“Our data provide a possible explanation for why in the first weeks of the year there was no sharp decline as expected in the number of new difficult patients daily, despite deepening the vaccination campaign and the high efficacy of vaccines,” said Prof. Ran Blitzer, director of Clalit Research Institute and head of the fund.

Prof. Blitzer // Photo: Yuval Chen

“The results of the study show that since the beginning of 2021 the clinical characteristics of Corona disease have changed and the risk of serious disease has increased significantly among the unvaccinated population, hence the British strain is not only more contagious but also more dangerous. These results are consistent with UK reports of increased strain violence. The new, “he noted.

“Therefore, had it not been for the initial curb in morbidity due to the closure and effects of the vaccine operation, we would now see a significantly higher number of critically ill patients flooding our hospitals. His influence, “he added.

The vaccination campaign continues // Photo: Moshe Ben Simhon and Newsenders

“We find it appropriate to publish these findings before scientific publication and peer review, to warn the public about the need to exercise caution during Purim. We have come out of quarantine into a new and unfamiliar reality, of a more contagious and violent strain. Even those who have been vaccinated, and certainly those who have not yet – “It is time to proceed in a moderate and careful manner and to follow the guidelines of the Ministry of Health. And of course – this is the time for those who have not yet been vaccinated to do so now,” wrote Prof. Blitzer.

.Source