A study by Klalit and Harvard: very high efficiency for the corona vaccine

Encouraging findings in a huge study published by the Klalit Research Institute: it shows that the corona vaccine is very effective in preventing infection and preventing serious illness in all age groups. After the second dose of the vaccine: a 94% reduction in morbidity and a 92% reduction in serious illness * also in the issue of side effects - indeed there is a rate of 1-5 vaccinees who get pericarditis out of every 100 vaccinees, but the risk of this from those who get the disease itself is double, not to mention About other side effects that the disease has and that were not found in the vaccine study

The Klalit Research Institute published in the scientific journal The New England Journal of Medicine the results of the large-scale study it conducted regarding the effectiveness of the Pfizer company's vaccine against the corona virus. He conducted the research in collaboration with researchers from Harvard University. Last week the vaccine received permanent approval from the FDA.

The research shows that The vaccine against the corona virus of the Pfizer company very effectively prevents both symptomatic infection and severe morbidity in all age groups. Vaccine doses given in general 6,731,622 first dose: 3,015,996Second dose: 2,776,896(92% of the first batch) updated as of 26.08.21 at 20:16for more data

The risk of getting pericarditis from the disease itself is much higher than from the vaccine

In this study conducted during mass vaccination on a national scale, the BNT162b2 vaccine was not associated with an increased risk of most of the side effects tested except for one - an excess risk of myocarditis (1 to 5 events per 100,000 people). The risk of many symptoms, including inflammation of the heart muscle increased significantly after SARS-CoV-2 infection.

Those who have contracted SARS-CoV-2 have a much greater risk, up to more than 2 times - 11 events per hundred thousand people and in addition the patients also suffer from many side effects including pericarditis, arrhythmias, deep vein thrombosis, pulmonary embolism, myocardial infarction, bleeding intracranial and thrombocytopenia.

Already two weeks after the first dose, partial effectiveness is achieved

The results of the study show that two weeks after the first dose, a 57% reduction in morbidity, a 62% reduction in severe disease and a 72% reduction in mortality was observed.

21 to 27 days after the first vaccination (a period when in the vast majority of cases the second vaccine dose was also given) a reduction of morbidity by 66%, a reduction of severe disease by 80% and a reduction of mortality by 84% was observed.

After full vaccination, i.e. one week after the administration of the second dose of the vaccine, the morbidity rates from corona decreased by 94% and the rate of severe disease decreased by 92%.

Table: The effectiveness of the corona vaccines

	14 to 20 days after the 1st dose 21 to 27 days after the 1st dose	A week after the 2nd dose
Morbidity	57%- 66% -	94% -
serious illness	​62%- 80% -	​92%-
mortality	​72%- 84% -	between 85%- to 100%-​

As part of the study, data on about 600 people who were vaccinated in Israel were examined against about 600 unvaccinated people who were the control group. The study provides for the first time a wide-ranging picture, using an advanced peer-reviewed research method, of the effectiveness of the vaccine against the corona virus in the context of mass vaccination - after the first dose and after the second dose.

The effectiveness of the vaccine is maintained even among those aged 70 and over

The size of the sample also made it possible to evaluate the effectiveness of the vaccine for specific subpopulations. In terms of age groups, the effectiveness of the vaccine was found to be similar in the different age groups, including those aged 70 and over. Among the subgroup of vaccinees with three or more underlying diseases, it was found that the vaccine reduces morbidity from corona by 89% compared to 94% in the general population.

According to Prof. Ran Blitzer, director of the Klalit Research Institute and of Klalit's innovation system, "the study unequivocally shows that the vaccine is highly effective in preventing illness and severe illness from the corona virus one week after the second dose and provides only partial protection in the earlier weeks after the vaccination.

These results are similar to the results reported in the original Pfizer clinical study. The practical significance of the study is clear, and I urge everyone who has not yet been vaccinated to do so. The results correspond well with the latest trends in morbidity in Israel: a continuous decrease for a month in the rate of hospitalization and the rate of severe morbidity in the older age groups that were vaccinated first, and a similar picture three weeks later among the younger age groups, where the vaccination only started a few weeks later."

The following researchers participated in the study: Dr. Naa Dagan, Dr. Noam Barda, Dr. Eldad Kaptan, Oren Miron, Shay Partchik, Prof. Mark Katz and Prof. Ran Blitzer from the Klalit Research Institute as well as Prof. Miguel Hernan, Prof. Mark Lipshitz and Prof. Ben Rice from Harvard University.

for the scientific article

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