The Ad26.COV2.S vaccine has demonstrated clinical efficacy against symptomatic COVID-19, including against the B.1.351 variant that is partially resistant to neutralizing antibodies. However, the immunogenicity of this vaccine in humans against SARS-CoV-2 variants of concern remains unclear. Here we report humoral and cellular immune responses from 20 Ad26.COV2.S vaccinated individuals from the COV1001 phase 1/2 clinical trial against the original SARS-CoV-2 strain WA1/2020 as well as against the B.1.1.7, CAL.20C, P.1., and B.1.351 variants of concern. Ad26.COV2.S induced median pseudovirus neutralizing antibody titers that were 5.0- and 3.3-fold lower against the B.1.351 and P.1 variants, respectively, as compared with WA1/2020 on day 71 following vaccination. Median binding antibody titers were 2.9- and 2.7-fold lower against the B.1.351 and P.1 variants, respectively, as compared with WA1/2020. Antibody-dependent cellular phagocytosis, complement deposition, and NK cell activation responses were largely preserved against the B.1.351 variant. CD8 and CD4 T cell responses, including central and effector memory responses, were comparable among the WA1/2020, B.1.1.7, B.1.351, P.1, and CAL.20C variants. These data show that neutralizing antibody responses induced by Ad26.COV2.S were reduced against the B.1.351 and P.1 variants, but functional non-neutralizing antibody responses and T cell responses were largely preserved against SARS-CoV-2 variants. These findings have implications for vaccine protection against SARS-CoV-2 variants of concern.
About The Expert
Galit Alter
Jingyou Yu
Jinyan Liu
Abishek Chandrashekar
Erica N Borducchi
Lisa H Tostanoski
Katherine McMahan
Catherine Jacob-Dolan
David R Martinez
Aiquan Chang
Tochi Anioke
Michelle Lifton
Joseph Nkolola
Kathryn E Stephenson
Caroline Atyeo
Sally Shin
Paul Fields
Ian Kaplan
Harlan Robins
Fatima Amanat
Florian Krammer
Ralph S Baric
Mathieu Le Gars
Jerald Sadoff
Anne Marit de Groot
Dirk Heerwegh
Frank Struyf
Macaya Douoguih
Johan van Hoof
Hanneke Schuitemaker
Dan H Barouch
References
PubMed