George P. Einstein and Orien L. Tulp
Historically, epidemics occur about three times a century and pandemics about once a century, and each time a different infectious organism has been discovered to be the culprit. In addition, those individuals who also have comorbidities often entertain the greatest risk of the most serious complications of the illness. In January 2020, a novel coronavirus, SARSCoV-2, was identified as the cause of an outbreak of viral pneumonia of unknown origin in Hubei Province, Wuhan, China, having infected over 200 people and causing several deaths in the early phase of the outbreak. The illness, later named coronavirus disease 2019 (COVID-19), subsequently spread globally in a seemingly exponential manner and was soon determined to be the origins of a pandemic by the World Health Organization (WHO) within the first few months of its discovery and emergence. In the first three months after COVID- 19 emerged, nearly one million people were infected and 50,000 had succumbed due to complications of the illness. By six months into the outbreak the number of cases worldwide exceeded ten million and there were more than 500,000 deaths. To date, there have been roughly 62 million cases and over 800,000 deaths from COVID-19 just in the United States. One of the troubling observations about COVID-19 is that people who were infected with SARS-CoV-2, which some scientists estimate may be as high as 40%, can transmit the virus to others when asymptomatic and before they have developed overt symptoms or without ever having symptoms of disease at all. Once infected, the virus may infect multiple organs and tissues including brain, cardiovascular, pulmonary, and other organs and cause long lasting sequela. The NIH National Institute of Allergy and Infectious Diseases (NIAID) COVID-19 and others in cooperation with vaccine manufacturers research efforts have built upon earlier research on Severe Acute Respiratory Syndromes (SARS) and Middle East Respiratory Syndrome (MERS), also caused by strains of respiratory prone coronaviruses. The purpose of the present paper is to review the evolution and development of the MERS, SARS. and COVID-19 coronaviruses and their devastating impact on global healthcare resources and their delivery with the evolution of the COVID-19 pandemic.