The Health Ministry announced Wednesday that widespread serological testing would begin next week to help determine the extent of the population’s exposure to the coronavirus.
The ministry said the antibody tests would be performed throughout the country by health maintenance organizations, with some 70,000 people initially set to be tested.
Tens of thousands more will be tested later as part of the effort.
Some testing already began Wednesday in the predominantly ultra-Orthodox city of Bnei Brak, which in April became the first city in Israel to be placed under a strict lockdown due to its high infection rate.
The antibody tests are seen as a key component in finding out who already had the disease in order to better understand its spread and shape policy ahead of a possible second outbreak.
Health Minister Yuli Edelstein said the tests would give health officials a “better intelligence picture” on virus hotspots in the country.
“That way we can better deal with an additional wave of coronavirus if, God forbid, it breaks out,” he said in a ministry statement Wednesday.
The testing program was announced in early May by outgoing Health Ministry director-general Moshe Bar Siman-Tov, though it has since faced delays.
The results of an initial set of serological tests, which were detailed in a report Tuesday, indicated that some 200,000 Israelis, or 2.5 percent of the population, have had COVID-19 — more than ten times the confirmed number of patients.
The results indicate a far greater infection rate than previously thought — estimates by the Health Ministry and the National Security Council put the rate at no more than 1% of the population — but still nowhere near the 60% or so that is required to achieve herd immunity. It also indicates a far greater chance than previously thought for carriers to feel no symptoms.
The set of 1,700 antibody tests was conducted by a Health Ministry team led by Prof. Daniel Cohen, the acting head of Tel Aviv University’s School of Public Health, with help from the Magen David Adom ambulance service. Those tested are a representative sample of the population in age, gender and place of residence, the Haaretz daily said in its report Tuesday.
Antibody tests are different from the nasal swab tests currently used to diagnose active infections. Instead, the tests look for blood proteins called antibodies, which the body produces days or weeks after fighting an infection. Most use a finger-prick of blood on a test strip. An antibody test might show if the subject had COVID-19 in the recent past, which most experts think gives people some protection.
The reliability of the tests is said to be between 95% and 98%. They don’t say whether the person still has the coronavirus or if they have recovered.
The government hopes that by conducting widespread serological testing, it will be able to determine if Israel is approaching herd immunity or if it is unprepared for a resurgence of the virus.
Bar Siman-Tov has said that if only a small percentage of Israelis are found to have COVID-19 antibodies, that could indicate the country’s health system may become swamped during a future outbreak.
The antibody tests come as the country has seen an uptick in COVID-19 cases over the last week, raising concerns of the virus’s resurgence and a possible second wave.
Agencies contributed to this report.