Journal article

Neutralizing antibody levels are highly predictive of immune protection from symptomatic SARS-CoV-2 infection

David S Khoury, Deborah Cromer, Arnold Reynaldi, Timothy E Schlub, Adam K Wheatley, Jennifer A Juno, Kanta Subbarao, Stephen J Kent, James A Triccas, Miles P Davenport



Predictive models of immune protection from COVID-19 are urgently needed to identify correlates of protection to assist in the future deployment of vaccines. To address this, we analyzed the relationship between in vitro neutralization levels and the observed protection from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection using data from seven current vaccines and from convalescent cohorts. We estimated the neutralization level for 50% protection against detectable SARS-CoV-2 infection to be 20.2% of the mean convalescent level (95% confidence interval (CI) = 14.4-28.4%). The estimated neutralization level required for 50% protection from severe infection was significa..

View full abstract


Awarded by Australian Government Medical Research Future Fund

Awarded by NHMRC

Funding Acknowledgements

This work is supported by Australian Government Medical Research Future Fund awards GNT2002073 (to S.J.K., M.P.D. and A.K.W.), MRF2005544 (to S.J.K., A.K.W., J.A.J. and M.P.D.) and MRF2005760 (to M.P.D.), an NHMRC program grant GNT1149990 (to S.J.K. and M.P.D.), NHMRC CRE 1153493 (to J.A.T.), and by the Victorian Government (S.J.K., A.K.W., J.A.J.). J.A.J., D.S.K. and S.J.K. are supported by NHMRC fellowships. A.K.W., D.C., K.S. and M.P.D. are supported by NHMRC Investigator grants. This study was supported by the Jack Ma Foundation (K.S.) and the A2 Milk Company (K.S.). The Melbourne WHO Collaborating Centre for Reference and Research on Influenza is supported by the Australian Government Department of Health.