New York City, 27 September 2021 (dpa/MIA) - Pfizer reported the beginning of phase 2/3 EPIC-PEP study to evaluate the investigational oral antiviral candidate PF-07321332, co-administered with a low dose of ritonavir, for the prevention of COVID-19. The phase 2/3 randomized, double-blind, placebo-controlled study will enroll up to 2,660 healthy adult participants aged 18 and older. The company said the primary objective of the study will assess safety and efficacy for the prevention of confirmed SARS-CoV-2 infection and its symptoms through day 14. "If successful, we believe this therapy could help stop the virus early - before it has had a chance to replicate extensively - potentially preventing symptomatic disease in those who have been exposed and inhibiting the onset of infection in others," said Mikael Dolsten, Chief Scientific Officer and President, Worldwide Research, Development and Medical of Pfizer.