On May 27, 2021, Sanofi and GlaxoSmithKline started enrolment in their Phase 3 clinical study to assess the safety, efficacy and immunogenicity of their adjuvanted recombinant-protein COVID-19 vaccine candidate. The global randomized, double-blind, placebo-controlled Phase 3 study planned to includ more than 35,000 volunteers aged 18 and older from several countries, including sites in the US, Asia, Africa and Latin America.

The primary endpoint of the study is the prevention of symptomatic COVID-19 in SARS-CoV-2 na�ve adults, with secondary endpoints being the prevention of severe COVID-19 disease and prevention of asymptomatic infection.