Will serological tests in Bnei Brak show if Israel is immune to COVID-19?

Until now, Israel has been solely conducting molecular tests for the detection of the novel coronavirus.

 TEST TUBE with coronavirus label is seen at the end of January.  (photo credit: REUTERS)
TEST TUBE with coronavirus label is seen at the end of January.
(photo credit: REUTERS)
Israel hopes to test around 3,000 people in Bnei Brak to determine if they have developed immunity to the novel coronavirus, according to the Health Ministry. 
Dr. Asher Shalmon, head of the International Relations department for the ministry, told The Jerusalem Post that it is still unknown how many people in Israel had the virus since 80% of all people infected with SARS-CoV-2 are asymptomatic. Moreover, of those infected, it is still unclear if they can be infected a second time – the answer to which could impact Israel’s preparations for any second wave of corona.
He said the country plans to launch its first round of serological tests - tests that identify immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies - in the haredi city because a higher percentage of the population was infected. 
To date, 2,910 people out of the city's population of about 195,300 have been diagnosed with the virus, or about 1.5%.
The body quickly produces IgM antibodies for the initial fight against infection. IgG antibodies remain longer in the body, suggesting possible immunity.
“This will help us understand how come [incidence of] the virus was higher in certain communities and whether exposure to the virus creates a lasting immunity,” Shalmon said, noting that the Health Ministry’s expectation is that, like with most viruses, immunity is developed for at least a year or two if not for life. 
Until now, Israel has been solely conducting molecular tests for the detection of novel coronavirus, which determine if the virus is active in a patient’s system. These tests have been found to have a 30% false negative rate, meaning that 30% of those found to not have the virus actually have it. 
Shalmon said that Israel purchased around a million serological tests but has not yet determined a protocol for how and when to use them – even in Bnei Brak, despite reports that testing could start as early as next week. 

RAN SAAR, CEO of Maccabi Health Services, which insures 50% of Bnei Brak residents, said that the ministry has determined that anyone coming into a health fund lab for a routine or other blood test would also receive a serological test, which is administered the same way.
In addition, he said, the ministry plans to screen between 100 and 150 families who had at least one adult member infected with coronavirus. It also plans to test around 100 symptom-free families who are living in the same apartment building as a verified patient. 
Saar said it has still not been determined whether the tests done outside the lab will be conducted by the health funds or a third party, such as Magen David Adom.
He added that international data shows that around 8-10 times the number of known patients are infected, so he expects that the serological tests will show that as many as 25,000 to 30,000 residents of Bnei Brak had the virus. 
In the last two weeks, the number of molecular tests being conducted in Israel has dropped to between 4,000 and 9,000 per day, even though at one point as many as 13,000 people were being screened daily and the county has the capacity to test up to 20,000 people. 
Saar said that the Maccabi testing center in Jaffa, for example, which used to be open 24 hours a day, is now only operating for three hours per day – and that half of the people are being screened to ensure they are not coronavirus positive ahead of routine medical procedures. 
He stressed the importance of serological testing running through the health funds.
“The biggest mistake in the testing setup in March and April was the fact that it was not given to the health funds from the start,” Saar said. “Tests were being taken by MDA and then sent to 31 labs and then to the Health Ministry and then to the health funds, which resulted in many mistakes and real chaos.”
A review of testing practices by the Knesset Coronavirus Committee found that results were often not delivered to patients for as many as five to seven days. Now, results arrive within 24 hours.
“Three weeks ago, Maccabi started testing... 30% of results are received by patients in 12 hours, and 80% in 24 hours,” he said. “Obviously, if we are preparing for the winter – if it will be a hectic winter in which we’ll have regular flu and coronavirus – I am sure vis-a-vis corona testing, we will operate in a much better manner than we were operating in March and April.” 
Shalmon noted that once the Bnei Brak serological survey is under way, the next places where the country is expected to screen are senior living facilities and then other ultra-Orthodox neighborhoods.  But he cautioned not to focus too much on the impact of this testing yet.
“We don’t yet know where and how to use these tests,” he reiterated. “Performing this survey will allow us to make a decision about whether it will be wise to use these tests on people returning from abroad or on essential workers. All these ideas should be considered. But we are a good few weeks from having a common, practical guideline for how to use serological tests.”