May 19, 2021

Neutralizing Antibody Levels Are Highly Predictive of Immune Protection from Symptomatic SARS-CoV-2 Infection

Category: Article Summary

Topic: Vaccines and Immunity

Keywords (Tags): immunity, vaccines

• Vaccine efficacy of 7 COVID-19 vaccines correlated well with reported vaccine-elicited neutralization titers (r=0.9), according to an analysis of phase 3 vaccine trial data. Using data from the trials and neutralization data from cohorts of convalescent patients, the authors estimated that levels of vaccine-elicited anti-SARS-CoV-2 neutralizing antibodies required for 50% protection against detectable SARS-CoV-2 infection was 20% of the mean convalescent neutralization level among patients with previous infection. Neutralization levels required for 50% protection against severe disease was only 3% of the mean convalescent level. Using modeling to estimate decay of the neutralization titer over the first 250 days after immunization, the authors predict that while vaccine-elicited neutralization levels may decline significantly over time, protection against severe disease may still largely be retained.

Khoury et al. (May 17, 2021). Neutralizing Antibody Levels Are Highly Predictive of Immune Protection from Symptomatic SARS-CoV-2 Infection. Nature Medicine. https://doi.org/10.1038/s41591-021-01377-8