Antibody tests a mystery for CT docs

Tests that can determine whether someone has developed antibodies against COVID-19 are becoming more common, but health experts said it’s still unclear whether having antibodies protects against reinfection.

“We don’t want to give people the wrong impression, because we don’t know what this means yet, if you have antibodies,” said Dr. Zane Saul, chief of infectious disease at Bridgeport Hospital.

Antibodies are the proteins the body uses to neutralize an infection. The presence of antibodies against a certain illness typically means a person was sick and recovered from the infection. Sometimes, the presence of antibodies means a person has protection against reinfection. That’s the case with illnesses such as chicken pox, where being infected once usually means a person won’t get it again, Saul said.

But, he said, with other illnesses — such as the flu — the immunity is only temporary. It’s unknown where along the spectrum the COVID-19 antibodies sit.

It’s unlikely that anyone will know how much protection COVID-19 antibodies offer for at least six to nine months, said Dr. Tom Balcezak, chief clinical officer for Yale New Haven Health System.

Tests for COVID-19 antibodies, also called serology tests, involve taking a blood sample, and examining it for the antibodies. According to the Centers for Disease Control and Prevention, “antibody tests should not be used to diagnose someone as being currently sick with COVID-19. To see if you have a current infection, you need a viral test, which checks respiratory samples, such as a swab from inside your nose.”

Saul said Bridgeport Hospital has antibody tests available, but testing isn’t widespread there yet — partly because of the uncertainty surrounding it, and because the hospital is focusing on those with active infections.

“We’re still working on patients and getting them through infection,” Saul said.