When Israeli students kicked off their school year on Wednesday, many of them were carrying a small white plastic coronavirus test in their backpacks. That is because parents were asked to screen their children using a rapid at-home antigen test to ensure that students do not bring the virus with them to school.
But what is a rapid antigen test? And how is it different from a PCR or serological test?
Dr. Nadav Soreq of Samson Assuta Ashdod Hospital helped answer the question in a new video provided to The Jerusalem Post.
Serological tests, Soreq explained, check a person’s immune system to see if that individual has ever been exposed to the virus in the past. These are the tests that the country attempted to use on children ahead of the school year.
If children had been infected with coronavirus and did not know it, the serological test would tell them. Children who have antibodies receive a “Green Pass” that keeps them out of isolation if a classmate gets sick and also allows them entry into gatherings and events.
In contrast, rapid tests and PCR tests “check a person’s condition today,” Soreq said.
Rapid tests can be performed on the spot and are inexpensive. These are the home tests that parents used on Tuesday. However, they are less sensitive than PCR tests, and therefore their role is to provide an “initial filtering.”
PCR tests are molecular tests performed in a laboratory.
“The tests are expensive and complex,” Soreq said. “They really give us a broad spectrum of results, and have a very high sensitivity.”
A PCR test can determine if a person is sick at almost any stage of the individual’s illness – the beginning or even after its peak. Therefore, it is these tests that are performed by health funds and hospitals to determine if a person truly has the virus.
People who take rapid antigen tests and receive a positive result are asked to visit their health fund to be rescreened with a PCR test to confirm the result and be entered into the country’s coronavirus data tracking system.
Until otherwise advised, a person who gets a positive result on either a rapid antigen or PCR test should isolate.
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