A empirical case study result showed that the prevention effect exceeded 95% if both Pfizer-Bioentech's COVID-19 vaccine was administered twice.
In an Israeli vaccination study published in the British medical journal Lancet, an analysis of health data from Israel that had vaccinated more than 5 million people as of the beginning of last month showed that the infection prevention rate was 95.3% and the survival rate was 96.7% one week after the second dose of the Pfizer vaccine. Appeared.
14 days after vaccination, these numbers rose to 96.5% and 98.0%, respectively.
The effect was markedly reduced with one dose.
From one week to two weeks after the first vaccination, the infection prevention rate was 57.5%, and the survival rate was only 77.0%.
The researchers emphasized, "It is an important result showing that the two doses significantly increase the immunity and preventive effect," he said. "You must complete the two doses."
This is the largest survey of actual vaccinators.
The study also validated the effectiveness of Pfizer's vaccine, particularly against major mutations.
During the study period, 232,268 cases of Corona 19 were reported, of which 95% were from the UK, the researchers said.
The researchers say that the Pfizer vaccine has been shown to be effective against mutations originating in the UK even in the elderly, but it has not proven its effectiveness against mutations in South Africa.
Commentators in the journal assessed the study as showing that high vaccination rates could be a way to end the pandemic.
However, he pointed out that the short supply of Pfizer vaccines, high cost, and restrictions on cryogenic distribution are a major obstacle to the spread of the Israeli model globally.