A Study to Learn About a Repeat 5-Day Treatment With Nirmatrelvir/Ritonavir in People With Return of COVID-19 Symptoms and SARS-CoV-2 Positivity After Finishing Treatment With Nirmatrelvir/Ritonavir

An Interventional, Efficacy and Safety, Phase 2, Randomized, Double-Blind, 2-Arm Study to Investigate a Repeat 5-Day Course of Nirmatrelvir/Ritonavir Compared to Placebo/Ritonavir in Participants at Least 12 Years of Age With Rebound of COVID-19 Symptoms and Rapid Antigen Test Positivity