To the Editor:

“Flaws Hindering Antibody Testing” (front page, April 20) outlines the pitfalls of antibody testing. Antibody testing varies, and there are tests available with good sensitivity and specificity that can be used effectively. A reasonable strategy can be implemented for returning to normal economic activity in the United States.

First, test all front-line health care providers for antibodies. Those who test antibody positive, presumably immune to the virus, can treat patients without cumbersome protections now needed. This will free up more protective equipment for providers testing negative.

Next, test everyone in areas with high Covid-19 infection rates. The large-scale testing necessary would require implementing the Defense Production Act. Laboratories across America would divert resources to manufacturing newly F.D.A.-approved antibody tests.

New York City would be the ideal place to start. Because of subway commuting contact, a large percentage of New Yorkers may test positive but were asymptomatic. Anyone certified as testing positive can return to work, go to restaurants and resume other normal activities.