Randomized Clinical Trial for the Prevention of SARS-CoV-2 Infection (COVID-19) in Healthcare Personnel

Healthcare workers are particularly at risk of SARS-CoV-2. In the absence of a vaccine, other strategies aiming to reduce the development of COVID-19 in the population, more specifically in healthcare workers is being sought. Administration of effective drugs to people at risk of developing an infectious disease is well accepted and is part of clinical practice. To date there are few on-going randomized clinical trial on Pre-exposure prophylaxis (PrEP) evaluating chloroquine and hydroxychloroquine efficacy for health care workers and other groups at high risk. Existing recent and scarce literature shows that RNA synthesis nucleos(t)ide analogue inhibitors, acting as viral RNA chain terminators, like TDF, abacavir or lamivudine, amongst others, could have an effect against SARS-CoV-2 infection. Worldwide, there is broad evidence of the use, safety and tolerability of hydroxychloroquine (200 mg) and TDF/FTC (245 mg/200 mg). This study aims to assess the efficacy of a daily single dose of TDF (245 mg)/FTC (200 mg), a daily single dose of HC (200 mg), a daily single dose of TDF (245 mg)/FTC (200 mg) plus HC (200 mg) versus placebo, during 12 weeks in: (1) reducing the incidence of symptomatic disease and (2) reducing clinical severity COVID-19 among hospital healthcare workers aged 18 to 70 years in public and private hospitals in Spain. Sample size calculations are based on the primary outcome; number of symptomatic confirmed infections by SARS-CoV-2. Briefly, 4.000 participants will be assigned to one of the 4 groups, through 1:1:1:1 randomization. Duration of prophylactic treatment will be 12 weeks from early April 2020 till early July 2020. Follow up of participants will continue up to 4 weeks after last dose of treatment. All participants will be assessed on a monthly basis. Interim analyses will be performed on monthly bases.