Post Exposure Prophylaxis (PEP) in Healthcare Workers Exposed to COVID-19 Patients: A Double-blind Randomized Clinical Trial

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.