COVID-19 antibodies may offer at least partial protectionAmericans with COVID-19 antibodies displayed 10-fold increased protection against infection 90 days after testing compared with those who had no antibodies, according to a study published today in JAMA Internal Medicine.The study tracked more than 50% of the commercial antibody and diagnostic tests administered in the United States from Jan 8 to Aug 23, 2020, covering 3,257,478 people.
At the index test, 88.3% had a negative antibody test, 11.6% were positive, and 0.1% were excluded because of uncertain results.The researchers then followed the seropositive and seronegative groups for a median of 54 and 47 days, respectively.