Is Hydroxychloroquine a Possible Post-Exposure Prophylaxis Drug to Limit the Transmission to Health Care Workers Exposed to COVID19?
Pagliano et al.
, Is Hydroxychloroquine a Possible Post-Exposure Prophylaxis Drug to Limit the Transmission to Health Care..
, Clin. Infect. Dis., 2020 Mar 24, doi:10.1093/cid/ciaa320 (Theory)
CQ and HCQ inhibit replication at early stages of infection, no similar effect reported for other drugs which are only able to interfere after cell infection. Large volume of existing data on safety. (8/23: we corrected the classification of this study)
Pagliano et al., 24 Mar 2020, peer-reviewed, 5 authors.
Abstract: Correspondence: H. Yi, South Southern University of Science
and Technology, Shenzhen, China (firstname.lastname@example.org).
Clinical Infectious Diseases® 2020;71(15):884–7
© The Author(s) 2020. Published by Oxford University Press for
the Infectious Diseases Society of America. All rights reserved.
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Is Hydroxychloroquine a
Prophylaxis Drug to Limit the
Transmission to Healthcare
Workers Exposed to Coronavirus
To the Editor—We read with great interest the study by Yao et al  reporting
that hydroxychloroquine has better antiviral activity than chloroquine against
severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is associated
with a high lung-to-plasma concentration
ratio and immunomodulatory effects.
Moreover, the authors highlighted that
hydroxychloroquine half maximal effective
concentration values “tended to decrease
with longer incubation times” and that, in
the simulation model, the lung trough concentrations were still above the target concentration on day 10 after a 5-day course of
Besides household contacts, SARSCoV-2 can be acquired in hospital settings, with healthcare workers (HCWs)
attending at invasive procedures on the
respiratory tract (ie, intubation, endotracheal tube aspiration, or bronchoscopy)
at the highest risk. Accidently infected
HCWs represent an important source of
infection during the period that they are
asymptomatic or presymptomatic, as they
can transmit the virus to household contacts and to patients seeking medical care
for reasons unrelated to SARS-CoV-2
infection. For these reasons, we suggest
preventive strategies for those accidentally exposed to SARS-CoV-2 such as
preexposure or postexposure prophylaxis
to avoid viral transmission, as largely accepted for those exposed to other viral
agents such as human immunodeficiency
virus (HIV) .
Chloroquine and hydroxychloroquine
are able to inhibit replication at early stages
of viral infection, increasing endosomal
pH at the time of virus/cell fusion, as well
as impairing the glycosylation of cellular
receptors of many viruses including coronavirus . In contrast, no similar effect
on early phases of coronavirus infection
has been reported for other drugs proposed for SARS-CoV-2 treatment, which
are able to interfere only after cell infection, affecting protease cleavage (protease
inhibitors) or viral genome replication
(remdesivir or ribavirin). These effects of
chloroquine on early phases of viral replication permit the attenuation of vertical
transmission in an animal model of Zika
virus infection, significantly reducing
brain viral load, and make cells refractory to SARS-CoV infection in an in vitro
model [4, 5].
Hydroxychloroquine, the HIV protease inhibitors (particularly lopinavir),
ribavirin, and remdesivir are the most
promising drugs proposed for coronavirus disease 2019 (COVID-19) treatment, but currently no drug has been
proposed for postexposure or preexposure prophylaxis for those accidently exposed to SARS-CoV-2 .
On the basis of these investigations, we
believe that hydroxychloroquine can be
effective in preventing respiratory tract
invasion in HCWs exposed to SARSCoV-2 and that hydroxychloroquine
administration as a prophylactic agent
could be particularly useful for HCWs
attending to high-risk procedures on the
respiratory tract in COVID-19 patients.
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be used based on risk/benefit analysis. No treatment, vaccine, or intervention
is 100% available and effective for all current and future variants. We do not
provide medical advice. Before taking any medication, consult a qualified
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