Antibody-mediated protection against symptomatic COVID-19 can be achieved at low serum neutralizing titers [article]

Pete Schmidt, Kristin Narayan, Yong Li, Chengzi Kaku, Michael Brown, Elizabeth Champney, James Geoghegan, Maximiliano Vasquez, Eric Krauland, Thomas Yockachonis, Shuangyi Bai, Bronwyn Gunn (+3 others)
2022 medRxiv   pre-print
Multiple studies of vaccinated and convalescent cohorts have demonstrated that serum neutralizing antibody (nAb) titers correlate with protection against COVID-19. However, the induction of multiple layers of immunity following SARS-CoV-2 exposure has complicated the establishment of nAbs as a mechanistic correlate of protection (CoP) and hindered the definition of a protective nAb threshold. Here, we show that a half-life extended monoclonal antibody (adintrevimab) provides approximately 50%
more » ... otection against symptomatic COVID-19 in SARS-CoV-2-naive adults at low serum nAb titers on the order of 1:30. Vaccine modeling supports a similar 50% protective nAb threshold, suggesting low levels of serum nAb can protect in both monoclonal and polyclonal settings. Extrapolation of adintrevimab pharmacokinetic data suggests that protection against susceptible variants could be maintained for approximately 3 years. The results provide a benchmark for the selection of next-generation vaccine candidates and support the use of broad, long-acting monoclonal antibodies as an alternative or supplement to vaccination in high-risk populations.
doi:10.1101/2022.10.18.22281172 fatcat:nu33zcyycjadbl25catt2eafbm