A study to assess, in a two-arm open-label cluster randomized clinical trial, the efficacy of a 5-day course of LPV/r treatment in preventing COVID-19 in asymptomatic individuals exposed to a SARS-CoV-2 documented index patient, compared to surveillance alone.

Inclusion criteria:

1. Documented close contact with a person with either a PCR-confirmed SARS-CoV-2 or a positive rapid SARS-CoV-2 antigen test (as per standard of care).
2. Enrolment of the participant no more than 7 days since last contact with index case;
3. ≥ 16 years of age;
4. Informed consent as documented by signature (including parent's or legal guardian's signature if the participant is between 16 and 18 y.o.).

Exclusion criteria*:

1. Fever (temperature >38.0°C) and/or respiratory symptoms (cough, dyspnea) and/or new anosmia/ageusia;

2. Individuals with previous confirmed SARS-CoV-2 infection, dating within the last six months ;

3. Known impairment of liver function;

4. Known hypersensitivity to the study medications;

5. Use of any medications that are contraindicated with lopinavir/ritonavir using the website www.hiv-druginteractions.org/checker

6. Individuals on boosted protease inhibitor (other than LPV) or boosted elvitegravir as part of an antiretroviral therapy

7. Inability to be followed-up for the trial period

8. Documented vaccination against SARS-CoV-2

   • Where necessary, additional biological and clinical assessment will be performed, based on clinical judgement.