
https://news.emory.edu/stories/2020/05/coronavirus_antibody_study_sheds_light_on_immunity/index.html
“New research from Emory University indicates that nearly all people hospitalized with COVID-19 develop virus-neutralizing antibodies within six days of testing positive. The findings will be key in helping researchers understand protective immunity against SARS-CoV-2 and in informing vaccine development.
The test that Emory researchers developed also could help determine whether convalescent plasma from COVID-19 survivors can provide immunity to others, and which donors’ plasma should be used.”