1. COVID-19 pandemic
The emergence and re-emergence of infectious diseases in recent years demand national health care systems to develop effective surveillance mechanisms, diagnostic, treatment, and preventive strategies. The last two decades witnessed the outbreak of several viral infections with epidemic and pandemic potentials, most of which are zoonotic. These include severe acute respiratory syndrome-coronavirus (SARS-CoV), avian and swine-origin influenza viruses, Middle East respiratory syndrome-coronavirus, Ebola, Chikungunya, Zika, Nipah, and, more recently, severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2)[1]. SARS-CoV-2 represents family Coronaviridae, subfamily Orthocoronavirinae, and genus Betacoronavirus. By early November 2020, there have been more than 50 million confirmed cases of COVID-19 globally, with over 1 million reported deaths[2]. The ability of the virus to spread from person to person and the mortality associated with the infection pose serious threats to public health globally. The outbreak also had a major impact on global economy and lifestyle of human populations. The pathogenesis and transmission cycle of SARS-CoV-2 has not been elucidated completely, which hampers the development of effective treatment and preventive measures.