“A lot of us in infectious disease aren’t sure that the monoclonal antibodies are worth the effort,” said Dr. Christopher Ohl, a professor of infectious diseases at Wake Forest School of Medicine in Winston-Salem, North Carolina.

Some doctors on the front lines of treating Covid-19 patients have actually declined their allotments of the treatment, citing lack of evidence it really works.

“This is not something that’s ready for prime time,” said Dr. Pieter Cohen, an associate professor at Harvard Medical School and physician with the Cambridge Health Alliance Respiratory Clinic near Boston.

In fact, the Infectious Diseases Society of America, which helps guide clinicians, recommends against routine use of monoclonal antibodies, citing insufficient proof they work. The National Institutes of Health treatment guidelines also indicate there is not enough data to recommend their use.