Towards a Population-based Threshold of Protection for COVID-19 Vaccines

Overview

Journal Vaccine

Specialty Allergy & Immunology

Date 2021 Dec 22

PMID 34933765

Citations 92

Authors

David Goldblatt

Andrew Fiore-Gartland

Marina Johnson

Adam Hunt

Christopher Bengt

Dace Zavadska

Hilda Darta Snipe

Jeremy S Brown

Lesley Workman

Heather J Zar

David Montefiori

Xiaoying Shen

Peter Dull

Stanley Plotkin

George Siber

Donna Ambrosino

Affiliations

Soon will be listed here.

Abstract

Correlates of protection for COVID-19 vaccines are urgently needed to license additional vaccines. We measured immune responses to four COVID-19 vaccines of proven efficacy using a single serological platform. IgG anti-Spike antibodies were highly correlated with ID50 neutralization in a validated pseudoviral assay and correlated significantly with efficacies for protection against infection with wild-type, alpha and delta variant SARS-CoV-2 virus. The protective threshold for each vaccine was calculated for IgG anti-Spike antibody. The mean protective threshold for all vaccine studies for WT virus was 154 BAU/ml (95 %CI 42-559), and for studies with antibody distributions that enabled precise estimation of thresholds (i.e. leaving out 2-dose mRNA regimens) was 60 BAU/ml (95 %CI 35-102). We propose that the proportion of individuals with responses above the appropriate protective threshold together with the geometric mean concentration can be used in comparative non-inferiority studies with licensed vaccines to ensure that new vaccines will be efficacious.

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