A study on corona vaccine safety conducted by the Clalit Institute for Research in collaboration with Harvard University is published today (Thursday) in the New England Journal of Medicine.
The study was conducted based on an anonymous data analysis of Clalit's two million patients.
The first part examined post-vaccination side effects and compared the incidence of 25 potential side effects between vaccinated and unvaccinated.
The second part of the study examined side effects after infection with the corona virus and compared the prevalence of those 25 side effects between those who were infected with the corona and those who were not infected with the corona (all are not vaccinated).
Clalit's head of innovation, Prof. Ran Blitzer, said: "The study once again shows how safe the vaccine is, and how much the alternative of 'natural' morbidity in the corona virus without a vaccine puts the person at significant, heavier and much more common risk of serious comorbidity - and all beyond To the direct risk due to the lung disease caused by the corona virus and its severe complications. "
"We did not find in this study evidence of an excess frequency after vaccination of myocardial infarction, stroke, or arrhythmias, or of severe blood clotting disorders such as deep vein blood clots or pulmonary embolism, but we did find a significant excess of these symptoms after illness." "Naturally in the corona virus without a vaccine."
According to the study, few side effects were observed after vaccination compared to a high rate of serious side effects after infection with the corona virus in unvaccinated people.
Regarding the side effects associated with the vaccine - myocarditis: 2.7 excess cases per 100,000 vaccinated people were observed compared to 11 excess cases per 100,000 people who were infected with the corona virus and were not vaccinated.
However, side effects such as pericarditis, arrhythmias, heart attacks, strokes, pulmonary embolism, deep vein clots and severe kidney damage were observed at a higher rate in people who contracted corona but were not found to be increased after vaccination.
"In the current situation, with record morbidity rates in the State of Israel, the study highlights the need for those who have not yet been vaccinated to do so urgently - as an informed choice in light of extensive research information with a 'standard mark' of the world's leading scientific journal."
Added Prof. Blitzer.
Prof. Ben Rice, director of the Predictive Medicine Group at Boston Children's Hospital and Harvard Medical School, said that "so far one of the main motives for hesitation to get vaccinated has been a lack of information about possible vaccine side effects. This in-depth study provides reliable information on The safety of the vaccines, and we hope it will help those who have not yet decided on the vaccine. "
He added: "Anyone who has so far hesitated to get vaccinated due to concerns about rare side effects - such as myocarditis - should be aware that the risk of that side effect - myocarditis - is higher among unvaccinated people infected with the coronavirus."