Still, the relatively high prevalence of antibodies may partly explain why New York has not seen a significant uptick in cases over the past several months, even as the city has begun to reopen and some New Yorkers have begun to relax their social distancing. In interviews, epidemiologists have generally expressed surprise and relief at the relatively low rate of new infections in New York City, chalking it up to a variety of measures: widespread use of face coverings, adherence to social distancing recommendations and the continued ban on indoor dining and bars.
“If antibody tests are accurately identifying those who have been infected and if these antibodies are protective, are some communities in N.Y.C. close to achieving herd immunity, like Corona in Queens, for example,” Professor El-Sadr wrote in an email. “That is an intriguing thought.”