A Magen David Adom worker on the way to test a patient with symptoms of COVID-19 (coronavirus), in Jerusalem, March 16, 2020. Photo: Yonatan Sindel / Flash90.

JNS.org – According to a new study by Tel Aviv University in conjunction with Magen David Adom and the Israeli Health Ministry’s Center for Disease Control, some 2.5 percent of Israel’s population, or some 200,000 people, have had COVID-19, most of whom may not have developed symptoms.

As of Tuesday morning, the official number of Israeli COVID-19 cases was 17,219.

The numbers are based on tests for coronavirus antibodies conducted among 1,700 people throughout Israel. The tests examined data from samples of blood donations taken from the Magen David Adom blood bank as well as the blood bank of the Center for Disease Control.

Representative sampling conducted in other countries has found that rates of exposure to coronavirus are between 1 percent and 6 percent.

Interestingly, higher rates of exposure were found in Israelis ages 40-60, with some 3.5 percent of that group testing positive for coronavirus antibodies. Over 3 percent of tests from the Jerusalem area were positive for coronavirus antibodies, while only some 1 percent tested positive in the Haifa region.

The data from the study covers the cumulative exposure of the Israeli population until mid-April. Additional testing will be carried out later this month and at regular intervals.

This data has been presented to a team from the Health Ministry. Researchers recommended that in light of the low rate of exposure, which points to the absence of any herd immunity to coronavirus, Israel maintain the measures currently in place to check the spread of the virus.

“The serological tests give us an overall picture of exposure to coronavirus and helps identify those who have been exposed to the virus in the past few months. This is the most sensitive measurement of the extent of exposure,” explained professor Danny Cohen, head of the School of Public Health at TAU and a member of the team appointed to handle the coronavirus epidemic in Israel.

“The number we received indicates that we are far from herd immunity, and until there is an active or passive vaccine, we need to be very careful when it comes to the population. With corona, we need an exposure of 50 percent to 60 percent of the population to provide any sort of herd immunity that, along with other preventative measures, will reduce the possibility of the virus making the rounds in the population,” said Cohen.

Meanwhile, the IDF has developed four working scenarios for a second wave of coronavirus: a rapid, out-of-control spread in the next few months; life alongside the virus; a second wave that will hit this winter; and the possibility that the virus will gradually die out on its own.

A report compiled by the IDF and the Health Ministry, delivered to top health administration officials Tuesday morning, attempts to predict what the next stages of the coronavirus epidemic in Israel will look like.

“There is data from laboratory studies that indicate that heat, humidity, and sunlight damage the stability of respiratory particles and the virus itself. However, these studies do not necessarily apply to people infecting each other, which usually happens as a result of prolonged close contact, and will apparently happen even if the virus’ stability is affected,” the report states.