The personnel responsible for caring of patients infected by the SARS-CoV-2 virus: doctors,
nurses and paramedics working at Intensive Care Units (ICUs)), are at high risk of SARS-CoV-2
infection. Epidemiological figures suggest a high morbidity and mortality of doctors
responsible for the care of infected individuals, a factor that darkens further the panorama
of the current pandemic. The present proposal has two specific aims: (i) to evaluate whether
hydroxychloroquine, used prophylactically at low dose (400mg/week for three months), protect
against SARS-CoV-2 infection; and (ii) to examine whether exhaustion and senescence of immune
system cells are associated to higher risk of SARS-CoV-2 infection. This is a PILOT STUDY, a
Phase III double-blind, randomized, placebo-controlled clinical study in which we assess the
clinical effect of the prophylactic administration of hydroxychloroquine vs. placebo to
healthcare workers working at our University Hospital (HUN). Participants in each arm (n =
43) will be administered with a unique loading dose of 800 mg of hydroxychloroquine the first
day followed by 400 mg/week for 90 days. The population to be studied (uninfected healthcare
personnel) will be highly exposed to SARS-CoV-2 infection. Taking into account that around
80% do not express symptoms or that these are mild, an active search should be made for
individuals who become infected while participating in the study. For this, once the informed
consent form is signed, the molecular test for the diagnosis of SARS-CoV-2 infection by
RT-PCR will be carried out every 4 days in order to determine as closely as possible the
moment the participant become positive. The results of the diagnostic RT-PCR tests will be
confronted with: (i) the results of immune monitoring of at least 30 immunological parameters
in leukocytes (number and phenotype of: PMN cells, monocytes, T- and B-lymphocytes and
NK-cells) and in plasma (levels of IL-2, IL-6, IL-7, IL-10, GM-CSF, TNF-a, IP-10, MCP-1,
MIP-IA, IL-1, CRP, Type IFN-alpha and IFN-betta), analyzed by automated flow cytometry
software such as tSNE, SPADE, FlowSOM, among others (see attached file); and (ii) the daily
recording of data on the presence or absence of signs and symptoms associated with SARS-Cov-2
infection. For the recording of immune monitoring 20mL blood samples will be taken at
eight-time points (day 0) and at 8, 15, 21, 30, 45, 60 and 90 days in order to monitor the
baseline of immune functionality throughout the 90 days of the study. In summary, this
proposal seeks to identify immunological markers of the immune system important for defense
against SARS-CoV-2, that may be useful as prognostic markers for clinical response and
treatment of patients with COVID-19, and also, to evaluates whether Hydroxychloroquine, used
prophylactically, has a role in protecting against SARS-CoV-2 infection in a group of
healthcare workers. If hydroxychloroquine, as we all hope, turns out to be an agent that
prevent SARS-Cov-2 infection, a significant group of healthcare workers at HUN at risk of
becoming ill during the epidemiological peak (expected May 1st), will be protected thanks to
their participation in this study.