inclusion criteria: - healthcare workers from the public and private spanish hospital network at risk of sars-cov 2 infection - not having a previous covid19 diagnosis - not having experienced covid19 symptoms from march 1st 2020 until randomization - understanding the purpose of the trial and not having taken any pre-exposure prophylaxis (prep) including hiv prep from march 1st 2020 until randomization - having a negative sars-cov 2 crp before randomization - having a negative urinary pregnancy test in the previous 7 days for premenopausal women - premenopausal women and males with premenopausal couples must commit to using a high efficiency anticonceptive method

inclusion criteria: - healthcare workers from the public and private spanish hospital network at risk of sars-cov 2 infection - not having a previous covid19 diagnosis - not having experienced covid19 symptoms from march 1st 2020 until randomization - understanding the purpose of the trial and not having taken any pre-exposure prophylaxis (prep) including hiv prep from march 1st 2020 until randomization - having a negative sars-cov 2 crp before randomization - having a negative urinary pregnancy test in the previous 7 days for premenopausal women - premenopausal women and males with premenopausal couples must commit to using a high efficiency anticonceptive method