Still, researchers found hope in the vaccine’s ability to quickly drive down cases among Israelis getting the shots.

“I find this pretty persuasive that we are seeing actual effects of population-level vaccination,” said William Hanage, an epidemiologist at the Harvard T.H. Chan School of Public Health who was not involved with the Israeli study…

Maccabi Healthcare Services reported Thursday that out of 416,900 people it had vaccinated, only 254 had gotten Covid-19 a week after their second dose. What’s more, all of the cases were mild. Comparing these rates to unvaccinated people, the researchers estimated that the vaccine has an effectiveness of 91 percent.

“The data continues to be very encouraging and the high efficacy of the vaccine is maintained and remains stable,” said Dr. Anat Ekka-Zohar, the director of the Division of Data and Digital Health at Maccabi.