More cases of COVID-19 pandemic are being reported daily around the world. It is highly
infectious and, over 7 million people have been infected and more than 400,000 people have
died globally till this date. Countries around the world are struggling to avoid the spread
of this pandemic. The most common symptoms of coronavirus disease are fever, fatigue, and dry
cough. Most people (approximately 80 percent) recover from the disease without special care.
The disease can be serious, and even fatal. Older people, and people with other medical
conditions (such as asthma, diabetes, or heart disease), maybe more vulnerable to becoming
severely ill. As the COVID-19 pandemic continues to affect communities throughout the world,
the search for effective drugs remains a priority. Scientists across the globe are working to
produce a vaccine, but unlikely to be available before 2021. Meanwhile, a growing number of
countries have taken a series of systematic measures to curb coronavirus spread, including
national lockdowns, meeting bans, school closings, closures of restaurants, bars, sports
clubs etc

Researchers used to evaluate the invitro effectiveness of several potential COVID-19
treatments, including chloroquine (CQ) and redmeveir (RDV). The findings were found
encouraging as 90 percent of the virus was inhibited by a low concentration of CQ and the
results for RDV were even better-with an even lower concentration of this drug, achieving a
virus inhibition of 90 percent. However, unless clinically verified, it cannot confirm these
drugs for the treatment of COVID-19 patients. It is not known how well these medications
function in people who are infected with COVID-19 and is still being studied. The first
patient reported to be infected with COVID -19 in the U.S. was treated with RDV. The
treatment started on the 7th day of hospitalization and on the 11th day after his symptoms
were first identified. He started showing signs of progress on the very next day, presumably
due to treatment with RDV. Further data, however, is required to confirm the effect of this
treatment.

Researchers in France have also been studying the effectiveness of hydroxychloroquine (HCQ)
in a single-arm regimen to treat people with COVID-19. HCQ (and, in some cases, also
antibiotic azithromycin) has been used in this study to treat individuals with the COVID-19
virus in one setting. Investigators measured the amount of virus in swabs taken from these
individuals and from a group of individuals who did not receive HCQ. A larger decrease in the
volume of the virus from the individuals receiving HCQ occurred on a span of six days.
However, the groups were not randomized. Individuals who did not receive HCQ were at various
medical facilities and not necessarily like the individuals in the HCQ group. The results are
intriguing. But it's important to note that scientists have expressed concerns about this
study. Indeed, after the publication of these findings, a statement has been released in the
journal that it did not meet the "expected standard" of research (6).

Moreover, these two drugs HCQ and RDV were designed primarily to fight other diseases and not
COVID-19. Few data are available indicating that either could have some interest in the
treatment of the disease, but its complete effect on COVID-19 patients is not known. One
reason why researchers are interested in this drug is the HCQ's ability to modulate the
inflammatory response. Inflammation is the natural reaction of the body to bacteria, viruses,
or other substances that attack it. Our immune system usually attacks and actively kills
infected cells or foreign bodies. But this response may often fail to function properly
particularly in autoimmune disorders where the body is mistakenly attacking itself. HCQ has
subtle effects on a wide variety of immune cells, and it may be that one of these effects
helps stimulate the body's ability to fight off Covid-19. The inflammatory response in
COVID-19 can be so strong that it causes serious damage to the lungs, that is why patients
with severe infections need ventilators

Another hypothesis on the rationale of the Antiviral activity of HCQ, is that HCQ may also
alter the ability of the virus to bind to the outside of a host cell in the first place.

The gold standard of a drug trial is a placebo-controlled, randomized, double-blind study.
One group of participants should receive the investigational drug and another group should
receive a placebo. The individuals in each arm of the study should be randomized; the
demographics of both groups should be similar. Finally, the participants should not know if
they are receiving the investigational drug or a placebo and the healthcare workers should
not know what they are administering. Only under these conditions, It can conclusively
determine the safety and efficacy of a potential treatment.

Center for Disease Control and Prevention (CDC) confirmed that there are no approved drugs
for COVID-19 treatment. Researchers around the globe, however, are researching different
medications for COVID-19 patients, including the drug Hydroxychloroquine, which is mainly
used for the treatment of Rheumatoid Arthritis and Malaria. Not enough data was obtained yet
to know how well all of these medications are functioning. Therefore, aim to perform a
randomized placebo-controlled trial to assess the impact of these medications on healthcare
workers who exposed for the treatment of COVID -19 patients in Qatar.

Rational to conduct a clinical trial on HCQ: It is considered as a weak base. Many viruses
enter the host cells via endocytosis, as a result of which they are initially taken up into
an intracellular compartment that is "typically fairly acidic" whereas; Hydroxychloroquine
would alter the acidity of this compartment, which can interfere with the ability of viruses
to escape into the host cell and start replicating. Another hypothesis on the rationale of
the Antiviral activity of HCQ, is that HCQ may also alter the ability of the virus to bind to
the outside of a host cell in the first place.

Hypothesis:

HCQ will be more safe and effective in comparison to placebo in the prevention of COVID 19
cases, in healthcare workers exposed to COVID 19 patients.