ABSTRACT
In order to investigate whether COVID-19 convalescent patients have developed antibodies that may protect from reinfection, we collected sera from COVID-19 convalescent patients approximately 10 weeks after confirmation of COVID-19 by qRT-PCR (group B, n = 25, 11 females, 14 males, age range: 18-70 years, median age 52.2) and included for control purposes sera from subjects obtained before the COVID-19 pandemic (historic control group P, n = 24, 13 females, 11 males, age range: 18-68 years, median age 43.2). Our findings suggest that a natural SARS-CoV-2 infection, similar to that observed previously for rhinovirus (RV) infections,9 does not induce a protective antibody response inhibiting the virus-receptor interaction in all infected patients and therefore underline the urgent need for the development of a SARS-CoV-2 vaccine. The molecular interaction assays could be useful for identifying subjects having developed protective antibodies and for screening candidate vaccines to induce antibodies that inhibit the RBD-ACE2 interaction once they have been validated.