COVID-19 is a virus that has infected more than 60 million people and is responsible for over 1 million deaths since it began in December of 2019. The virus began in Wuhan, Hubei Province, China, and by January 30, 2020, the disease had spread to many other countries around the world, sparking a global pandemic.
The infection is caused through the contraction of the SARS-CoV-2 viral strain. It belongs to a larger family of viruses known as coronaviruses, that were first identified in the 1960’s. Each of the viruses belonging to this family contain similar structures, including the presence of spiked protrusions on their surfaces. There are 4 classifications in this viral family: Alphacoronavirus, Betacoronavirus, Gammacoronavirus, and Deltacoronavirus. Each strain is classified into one of these four classifications based on its structure and genetics. The alpha and beta classes are commonly known to cause infections in mammals, specifically respiratory infections in humans and gastric infections in animals.
Over the years, scientists have established two general classes of coronaviruses; ones that commonly infect humans and ones that commonly infect animals. Several serious respiratory outbreaks have occurred over the years due to viral strains that infect animals crossing species and leading to human infections.
Middle East respiratory syndrome (MERS) is caused by MERS-CoV, highly pathogenic virus that has evidence of transmission from camels to humans. Severe acute respiratory syndrome (SARS) was also observed in those infected with SARS-CoV, which is also highly pathogenic and began in an animal species before crossing over to humans. Like the effects from these coronaviruses, when infected with SARS-CoV-2, the human host can display severe respiratory illnesses.