COVID-19: Vaccine effectiveness after first vaccine dose around 33 percent / News

Two weeks after a first vaccine dose, it appears that the number of infections is one third lower than in the unvaccinated. That’s what Ran Balicer, doctor-epidemiologist of the largest Israeli healthcare organizations Clalit Health Services, says. In view of the decision of Minister De Jonge not to keep all vaccines in stock for a second injection, such information is important. So reports Medical Contact.

Israel is in the spotlight because it is at the forefront of vaccination of the population. The real effect of a large-scale vaccination campaign will therefore have to be visible there first.

Currently, about a quarter of the population has received a first dose, and even 75 percent of the over-60s. About one in 40 Israelis has already received a second dose.

Effect from day 14
Comparative research has been conducted between 200,000 vaccinated and an equal number of unvaccinated people over 60, Balicer says. He has not yet published the results in a scientific journal. There is no clear difference in the number of infections until day 12 after the first injection, but from day 14 the percentage of PCR positive infections is one third lower in vaccinees.

That is a lot lower than previously assumed, partly by British policymakers who therefore dared to postpone the second injection in order to administer a first dose to as many people as possible as soon as possible. They assumed an effectiveness of 89 percent from two weeks after the first dose.

There are scientists who do not consider it an unfavorable result. These indicate that in the Israeli situation there may also be some group protection, as the unvaccinated people also come into contact with vaccinated people. The total number of infections in the entire group would therefore be lower, but the difference between the two would actually be smaller.

The total number of daily infections is still high in Israel. Balicer expects to see an effect from the vaccination campaign in the coming week. Within three weeks, the number of serious cases should fall by half according to his calculations.

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