Israel Bolsters Antibody Tests as Second Virus Wave Threatens

(Bloomberg) -- Israel is fortifying its national survey of exposure to the coronavirus as a second wave of infections threatens to plunge the country back into lockdown.

The buttressed program will begin rechecking positive results for antibodies to the pathogen, helping researchers understand the depth and duration of immunity, according to Yair Schindel, a member of the task force helping Israel's Health Ministry respond to the coronavirus. Antibody tests show whether someone has ever been infected, unlike viral tests that seek out active cases.

Countries around the world are trying to solve mysteries about the virus that has killed more than 500,000 people, starting with finding out how many people are infected. Centers for Disease Control and Prevention Director Robert Redfield said last month that U.S. cases might be 10 times as high as the 2.3 million then estimated.

Israel has more than 27,500 confirmed Covid-19 infections and about 1.2% of those people have died, compared with rates of more than 11% in Spain and close to 5% in the U.S. Data from a small study of 1,700 people last month suggested that as many as 270,000 Israelis may have caught the virus. The bigger survey under way may give a more definitive estimate of how deadly it is.

The country's health maintenance organizations have started using so-called sequential testing -- re-examining blood work that comes up positive for antibodies to covid-19 -- as part of the national survey that began this week. Test kits Israel bought have an accuracy rate in the high-90% range, and secondary testing would reduce mistaken positive results for coronavirus antibodies to about 5 out of every 100,000, Schindel said. Israel's Health Ministry didn't respond to a request for comment.

Minimizing error is imperative for the nationwide effort, targeted to reach about 80,000 people in the coming weeks, because that gives a clearer picture of how many people were actually infected and a cleaner window into the workings of the virus. That ultimately shapes how countries manage the pandemic.

Israel plans to track those who test positive to determine with greater certainty how long people remain infectious, which would help establish the most effective length for quarantines, Schindel said. The ministry will also track whether those same people show signs of catching the virus again.

‘Normal life'

The survey might also help determine when and whether exposed people are immunized, said Schindel, who is also the founding partner of health-tech venture capital firm aMoon.

“If we could prove that, you could then go back to work, visit your relatives, volunteer in the community,” he said. “You can get back to normal life.”

That remains a distant prospect for Israelis. Earlier this week, the government limited the size of public gatherings in response to the recent surge in new cases. After a punishing lockdown, the country is still struggling with high unemployment, while Israel's technology sector, the main driver of growth, is finding it difficult to secure financing.

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