Source: c19 Study
A live and ongoing index of study data from around the world documenting the use of hydroxychloroquine in treatment at various stages of SARS-CoV-2 infection including pre-exposure prophylaxis and post-exposure prophylaxis is available at https://c19study.com/
Overwhelmingly, PrEP, PEP, and early treatment studies show high effectiveness of hydroxychloroquine, while late treatment shows mixed results.