Keywords

COVID-19; Drug therapy; BCG vaccine

Introduction

Corona Virus Disease 19 (COVID-19) is a pandemic infection now attained a position to cause a threat to the global health and it is showing the ill effects on the global economy. World health organization has declared COVID-19 as a Public health Emergency of International concern. All over the world several countries are dealing with the emergence of this pandemic and COVID warriors including doctors, nurses and other health care workers have become saviours working relentlessly to save the lives [1].

Description

Scientists from all over the world are in great research activity to find the solution for COVID-19 infection. Vaccine development and clinical trials are in progress all over the world to find an everlasting solution for the COVID-19 infection. Clinical and epidemiological evaluation of people susceptible to SARS-CoV-2 infection helps in understanding the pathogenesis and in-turn aid in better development of vaccines [2]. It is noted that certain people are more susceptible to COVID-19 than other people. The COVID-19 infection has been found to be associated with high severity in persons with the comorbidities including hypertension and diabetes [3]. A study from Yang et al found that the non- survivors have been associated with the cerebrovascular disease and diabetes. Similarly a study from Guan and co-workers has found the severe disease of COVID-19 has been associated with the hypertension, diabetes, cerebrovascular disease and coronary heart disease. 4. It is postulated that the expression of Angiotensin Converting Enzyme 2 (ACE-2), which is known as a receptor for SARS-CoV-2 is increased in patients with comorbidities such as diabetes and hypertension as these patients are treated with Angiotensin Converting Enzyme (ACE) inhibitors and angiotensin II type-I receptor blockers [4]. These ACE inhibitors favours the expression of ACE-2 receptors. Thus development of any vaccine or drug which favours high expression of the ACE, leads to the down regulation of expression of ACE-2 receptors [5,6].

The Bacille-Calmette Guerin (BCG) is a tuberculosis vaccine is in use for the long time. Literature survey revealed that Schrier et al has found that the lung lavage has shown high expression of ACE with BCG induced chronic granulomatous pulmonary inflammation [7]. This concept might be applied for the reducing the number of ACE-2 receptors thereby decreasing the access ability of the SARS-CoV-2 to the receptor [8]. The BCG vaccine is known to induce trained immunity and it allows quicker inflammatory response, it is known to induce protection against experimental infection with yellow fever vaccine strain. Recent experimental evidence has shown the BCG offers protection against various DNA, RNA viruses mediated through initiation of innate immune memory and heterologous lymphocyte activation leading to enhanced cytokine production [9]. Clinical trials are underway which aim to study the effect of BCG vaccination on the healthcare workers associated with the COVID-19 patients. WHO clarified that it doesn’t recommend the use of BCG vaccination for the prevention of COVID-19 and has to wait for the clinical trials results.

Conclusion

We conclude that in future due to safety, easy accessibility, low cost, its known affect in reducing the morbidity and mortality it might a possible useful strategy in dealing with COVID-19.

References

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