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Full vaccine effect only kicks in 15 days after second dose, Israeli HMO says

Israel, trailblazing with its ‘green passes,’ is giving them out too quickly, says Meuhedet health organization, bucking data from Pfizer

Nathan Jeffay is The Times of Israel's health and science correspondent

An attendee shows off a "green pass" (proof of being fully vaccinated against COVID-19 coronavirus disease) upon arrival at Bloomfield Stadium in Tel Aviv on March 5, 2021, before attending a "green pass concert" for the vaccinated, organized by the Tel Aviv municipality. (Photo by JACK GUEZ / AFP)
An attendee shows off a "green pass" (proof of being fully vaccinated against COVID-19 coronavirus disease) upon arrival at Bloomfield Stadium in Tel Aviv on March 5, 2021, before attending a "green pass concert" for the vaccinated, organized by the Tel Aviv municipality. (Photo by JACK GUEZ / AFP)

Israel is risking an unnecessary increase in morbidity by issuing green passes so soon after vaccination, and instead should make people wait another week, a healthcare provider is arguing, in research that may have global reverberations.

Meuhedet Healthcare Services reported on Monday, based on an analysis of more than 100,000 members, that vaccine effectiveness reaches 96 percent on the fifteenth day after full vaccination. From days 7 to 14, it is 89%.

In view of this, the fact Israel is giving green passes a week after full vaccination, instead of after two weeks, “may help to cause additional waves of illness,” said Dr. David Mosinzon, director of Meuhedet’s medical division.

The Health Ministry has not responded to the call, but if it changes policy, countries around the world that are closely monitoring Israel’s green pass experience to decide their own pandemic reopening strategies may follow suit.

A Meuhedet chart showing vaccine effectiveness among its members at various intervals (shown in days) after members were given their second shot (Meuhedet)

Israelis can now download an electronic green pass a week after their second vaccine shot, and the permit allows them to take full advantage of  the country’s reopening, which even includes entrance to restaurants and cafes as of Sunday.

The timing for green pass eligibility is based on data from Pfizer — the supplier of almost all the vaccines given in Israel so far — which consider people fully immune a week after receiving their second dose.

But Meuhedet said its research, which tracked 102,150 vaccinees for 35 days after receiving their second shot, found that 82 percent of all infections were in the first 14 days. While the number of infections is small — just 459 — it argued that delaying green pass status makes sense.

Health Ministry Director-General Chezy Levy during the announcement of the “Green Pass” certification on February 18, 2021 (Health Ministry)

“Removing social distancing regulations and giving the green pass as soon as eight days after the second vaccine is too early,” said Mosinzon.

“Hundreds of vaccinated who have not yet passed two weeks from the date of vaccination will, in line with the easing of their regulations, go in good faith to large events indoors,” he said. “They have been careful to get a second shot, and will go without knowing they may have contracted the virus before their body developed a high level of immunity, and without thinking they may be contagious.”

A Meuhedet graph showing how many members were confirmed COVID-positive on each of the first 35 days after they received their second vaccine shot (Meuhedet)

The Clalit healthcare provider disagreed, arguing that the need to get more people back to routine outweighed the value of delaying the green pass to reduce infections.

“One needs to strike a balance between de-risking the highest-risk indoor setting, and allowing a high enough proportion of the population to participate in the green pass activities to make them economically viable,” Clalit research chief Ran Balicer told The Times of Israel.

“At this point, the seven-day period seems to strike the right balance. In the future, as well-designed peer-reviewed analyses will reveal the actual difference in infection risk between day 7 and 14 after the second dose, we will be able to reconsider the policy.”

An Israeli citizen receives a COVID-19 vaccine, at a Meuhedet vaccination center in Jerusalem, on December 21, 2020. (Olivier Fitoussi/Flash90)

Experts note that various studies show people have high antibody levels by seven days after the second vaccine shot, and say that the onset of higher immunity after day 14 may point to protection achieved through other mechanisms.

“We do not have much experience with how immunological memory is established after challenging the immune system with mRNA vaccines,” Prof. Cyrille Cohen, head of the immunotherapy laboratory at Bar-Ilan University, told The Times of Israel.

“We know that they work and that they can generate excellent antibody responses but it is possible that at the cellular level, other mechanisms are building up during the second week that may explain the data observed.”

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