The ACTIV4c Post-Discharge study is testing if anticoagulation agents – blood thinners – improve recovery from COVID-19 for individuals after being discharged from the hospital.

The ACTIV3 study is testing if monoclonal antibody treatments -- laboratory-made proteins that mimic the immune system’s abilities -- improve recovery from patients hospitalized due to COVID-19.

The ACTIV3b study is testing if treatments improve recovery from patients hospitalized due to COVID-19.

The C4R observational study is collecting participant data and samples to better understand COVID-19 and the associated symptoms and side effects.

The ACTIV4A Inpatient study is testing if treatments that aim to prevent blood vessel injuries and blood clots improve recovery from patients hospitalized due to COVID-19.

The ACTIV4 Host Tissue platform is testing if treatments targeting the host-tissue response to SARS-CoV-2 infection can improve recovery and prevent worsening in patients hospitalized with COVID-19.

The ACTIV3c study is testing the optimal timing and number of mRNA vaccinations for patients recovering from a COVID-19 infection.