TY - JOUR
T1 - Correlates of protection against symptomatic and asymptomatic SARS-CoV-2 infection
AU - Oxford COVID Vaccine Trial group
AU - Feng, Shuo
AU - Phillips, Daniel J.
AU - White, Thomas
AU - Sayal, Homesh
AU - Aley, Parvinder K.
AU - Bibi, Sagida
AU - Dold, Christina
AU - Fuskova, Michelle
AU - Gilbert, Sarah C.
AU - Hirsch, Ian
AU - Humphries, Holly E.
AU - Jepson, Brett
AU - Kelly, Elizabeth J.
AU - Plested, Emma
AU - Shoemaker, Kathryn
AU - Thomas, Kelly M.
AU - Vekemans, Johan
AU - Villafana, Tonya L.
AU - Lambe, Teresa
AU - Pollard, Andrew J.
AU - Voysey, Merryn
AU - Adlou, Syed
AU - Allen, Lauren
AU - Angus, Brian
AU - Anslow, Rachel
AU - Asselin, Marie Claude
AU - Baker, Natalie
AU - Baker, Philip
AU - Barlow, Thomas
AU - Beveridge, Amy
AU - Bewley, Kevin R.
AU - Brown, Phillip
AU - Brunt, Emily
AU - Buttigieg, Karen R.
AU - Camara, Susana
AU - Charlton, Sue
AU - Chiplin, Emily
AU - Cicconi, Paola
AU - Clutterbuck, Elizabeth A.
AU - Collins, Andrea
AU - Coombes, Naomi S.
AU - Clemens, Sue Ann Costa
AU - Davison, Melanie
AU - Demissie, Tesfaye
AU - Dinesh, Tanya
AU - Douglas, Alexander D.
AU - Duncan, Christopher J.A.
AU - Emary, Katherine R.W.
AU - Ferreira, Daniela
AU - Hill, Helen
PY - 2021/9/29
Y1 - 2021/9/29
N2 - The global supply of COVID-19 vaccines remains limited. An understanding of the immune response that is predictive of protection could facilitate rapid licensure of new vaccines. Data from a randomized efficacy trial of the ChAdOx1 nCoV-19 (AZD1222) vaccine in the United Kingdom was analyzed to determine the antibody levels associated with protection against SARS-CoV-2. Binding and neutralizing antibodies at 28 days after the second dose were measured in infected and noninfected vaccine recipients. Higher levels of all immune markers were correlated with a reduced risk of symptomatic infection. A vaccine efficacy of 80% against symptomatic infection with majority Alpha (B.1.1.7) variant of SARS-CoV-2 was achieved with 264 (95% CI: 108, 806) binding antibody units (BAU)/ml: and 506 (95% CI: 135, not computed (beyond data range) (NC)) BAU/ml for anti-spike and anti-RBD antibodies, and 26 (95% CI: NC, NC) international unit (IU)/ml and 247 (95% CI: 101, NC) normalized neutralization titers (NF) for pseudovirus and live-virus neutralization, respectively. Immune markers were not correlated with asymptomatic infections at the 5% significance level. These data can be used to bridge to new populations using validated assays, and allow extrapolation of efficacy estimates to new COVID-19 vaccines.
AB - The global supply of COVID-19 vaccines remains limited. An understanding of the immune response that is predictive of protection could facilitate rapid licensure of new vaccines. Data from a randomized efficacy trial of the ChAdOx1 nCoV-19 (AZD1222) vaccine in the United Kingdom was analyzed to determine the antibody levels associated with protection against SARS-CoV-2. Binding and neutralizing antibodies at 28 days after the second dose were measured in infected and noninfected vaccine recipients. Higher levels of all immune markers were correlated with a reduced risk of symptomatic infection. A vaccine efficacy of 80% against symptomatic infection with majority Alpha (B.1.1.7) variant of SARS-CoV-2 was achieved with 264 (95% CI: 108, 806) binding antibody units (BAU)/ml: and 506 (95% CI: 135, not computed (beyond data range) (NC)) BAU/ml for anti-spike and anti-RBD antibodies, and 26 (95% CI: NC, NC) international unit (IU)/ml and 247 (95% CI: 101, NC) normalized neutralization titers (NF) for pseudovirus and live-virus neutralization, respectively. Immune markers were not correlated with asymptomatic infections at the 5% significance level. These data can be used to bridge to new populations using validated assays, and allow extrapolation of efficacy estimates to new COVID-19 vaccines.
U2 - 10.1038/s41591-021-01540-1
DO - 10.1038/s41591-021-01540-1
M3 - Article
SN - 1078-8956
VL - 27
SP - 2032
EP - 2040
JO - Nature Medicine
JF - Nature Medicine
IS - 11
ER -
SDG 3 Good Health and Well-being