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Master of Public Health

Immune correlates analysis of the ENSEMBLE single Ad26.COV2.S dose vaccine efficacy clinical trial

AUTHORS

Fong Y , McDermott AB , Benkeser D , Roels S , Stieh DJ , Vandebosch A , Le Gars M , Van Roey GA , Houchens CR , Martins K , Jayashankar L , Castellino F , Amoa-Awua O , Basappa M , Flach B , Lin BC , Moore C , Naisan M , Naqvi M , Narpala S , O'Connell S , Mueller A , Serebryannyy L , Castro M , Wang J , Petropoulos CJ , Luedtke A , Hyrien O , Lu Y , Yu C , Borate B , van der Laan LWP , Hejazi NS , Kenny A , Carone M , Wolfe DN , Sadoff J , Gray GE , Grinsztejn B , Goepfert PA , Little SJ , Paiva de Sousa L , Maboa R , Randhawa AK , Andrasik MP , Hendriks J , Truyers C , Struyf F , Schuitemaker H , Douoguih M , Kublin JG , Corey L , Neuzil KM , Carpp LN , Follmann D , Gilbert PB , Koup RA , Donis RO , , , , . Nature microbiology. 2022 11 10; 7(12). 1996-2010

ABSTRACT

Measuring immune correlates of disease acquisition and protection in the context of a clinical trial is a prerequisite for improved vaccine design. We analysed binding and neutralizing antibody measurements 4 weeks post vaccination as correlates of risk of moderate to severe-critical COVID-19 through 83 d post vaccination in the phase 3, double-blind placebo-controlled phase of ENSEMBLE, an international randomized efficacy trial of a single dose of Ad26.COV2.S. We also evaluated correlates of protection in the trial cohort. Of the three antibody immune markers we measured, we found most support for 50% inhibitory dilution (ID) neutralizing antibody titre as a correlate of risk and of protection. The outcome hazard ratio was 0.49 (95% confidence interval 0.29, 0.81; P = 0.006) per 10-fold increase in ID; vaccine efficacy was 60% (43%, 72%) at non-quantifiable ID (<2.7 IU ml) and increased to 89% (78%, 96%) at ID = 96.3 IU ml. Comparison of the vaccine efficacy by ID titre curves for ENSEMBLE-US, the COVE trial of the mRNA-1273 vaccine and the COV002-UK trial of the AZD1222 vaccine supported the ID titre as a correlate of protection across trials and vaccine types.

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