Anti-SARS-CoV-2 spike protein neutralizing antibody assay
infection
INFECTION, VIRUS
Assessment for the presence and amount of anti-SARS-CoV-2 spike protein neutralizing antibody activity in serum on Day 1 and on Days 10 and 29 was performed at Monogram Biosciences (South San Francisco, CA, USA) using the SARS-CoV-2 PhenoSense® nAB Assay. Serially diluted (1:40–1:2124 dilutions) serum samples were added to HEK293/ACE2 target cells before infection with a pseudotyped luciferase reporter virus expressing the spike protein from the original Wu-1 strain. Serum neutralizing titers were calculated based on the serum dilution needed to inhibit 50% luciferase signal compared with negative control serum.