COVID-19."In this study, we define the role of antibodies versus T cells in protection against COVID-19 in monkeys. We report that a relatively low antibody titre -- the concentration of antibodies in the blood -- is needed for protection," said study co-author Dan Barouch from Beth Israel Deaconess Medical Center (BIDMC) in the US."Such knowledge will be important in the development of next generation vaccines, antibody-based therapeutics, and public health strategies for COVID-19," Barouch said.Earlier studies had suggested that SARS-CoV-2 infection protects rhesus macaques from re-exposure, following which Barouch and his colleagues purified and collected antibodies from the monkeys that had recovered from infection.They administered the.