Developing immunity to COVID-19, a disease with no known cure, is a matter of debate, and now the World Health Organization is warning there is no evidence an antibody test means an individual is immune.
"These antibody tests will be able to measure that level of serology presence, that level of antibodies, but that does not mean that somebody with antibodies" is immune, according to WHO's Dr. Maria Van Kerkhove, the head of emerging diseases and zoonosis, CNBC reported.
It is also unproven a patient recovered from COVID-19 will not be able to contract the virus again.
According to Dr. Mike Ryan, executive director of WHO's emergencies program,"Nobody is sure whether someone with antibodies is fully protected against having the disease or being exposed again," per CNBC.
"Plus some of the tests have issues with sensitivity. They may give a false negative result.
"With regards to recovery and then reinfection, I believe we do not have the answers to that," he added. "That is an unknown."
The antibody test can show someone had the infection, but it cannot determine whether they are fully recovered, much less immune, according to WHO experts.
"What the use of these tests will do will measure the level of antibodies," Van Kerkhove said at a news conference at WHO's Geneva headquarters, per the report. "Right now, we have no evidence that the use of a serological test can show that an individual is immune or protected from reinfection."
President Donald Trump has said at recent coronavirus task force daily briefings the antibody tests are being rapidly processed at the U.S. Food and Drug Administration and might help in the "Opening up America Again" three-phase rollout across states.
A Shanghai study did find some patients had "no detectable antibody response," while others had a very strong response, according to Kerkhove.