An Israeli doctor is concerned that some recovered COVID-19 patients may not have any immunity, after her employees were given blood tests and the only two who were known to have carried the virus were found to be antibody-free.
“It is worrying [to consider] why they don’t have antibodies,” said Margarita Mashavi, head of internal medicine at Wolfson Medical Center in Holon, adding that as antibodies give protection against reinfection, she is concerned it may mean they aren’t immune.
Last week, researchers at Tel Aviv University announced they had determined that everyone who gets coronavirus has antibodies for at least two months, saying this offers some reassurance on the worryingly uncertain topic of immunity.
Mashavi sent 30 employees who had worked on coronavirus wards for Health Ministry serological testing, including the only two who were known to have had the coronavirus. Both had been confirmed positive by several swab tests around a month and a half ago and were hospitalized.
“We had sick people who had PCR [swab] tests and all the symptoms, but when we did antibody tests they were negative,” Mashavi said, discussing analysis that took place for two key antibodies, immunoglobulin G and immunoglobulin M.
She added that it wasn’t a matter of antibody levels dropping, but “they had no antibodies at all.”
Mordechai Gerlic, the Tel Aviv University researcher who announced last week that everybody has antibodies, said he regards the numbers at Wolfson to be too small to have significance.
Still, Mashavi thinks that while it is “too early to reach conclusions” based on the results she received, they are too surprising to be ignored.
“It’s not a lot of people but this is still important,” she said, arguing that if they pose a challenge to assumptions about immunity, they should be investigated, and if they point to a problem with testing reliability, this should be addressed.
“We need to check and possibly change the test method and the kits, and if [there is a problem with them], this is also really important to investigate,” Mashavi said.