Clinical trial protocols of repurposed prophylaxis for COVID-19: A review

Efficient therapeutic strategies are needed to counter the COVID-19 pandemic, caused by the SARS-CoV-2 virus. In a context where specific vaccines are not yet available, the containment of the pandemic would be facilitated with efficient prophylaxis. We screened several clinical trials repositories and platforms in search of the prophylactic strategies being investigated against COVID-19 in July 2020. Up to July 5, 2020, only one clinical trial result was published, although we found 112 clinical trial protocols targeting medical workers (n = 70, 63%), patients relatives (n = 20, 18%) or individuals at risk of severe COVID-19 (n = 14, 13%). (Hydroxy)chloroquine was the most frequently evaluated treatment (n = 69, 62%), before BCG vaccine (n = 12, 11%), this followed by numerous antivirals and immune enhancers. Ninety-eight (88%) clinical trials were randomized with a median of planned inclusions of 530 (IQR 258–1299). Both pre- and post-exposure prophylaxes are investigated.