An electron micrograph of SARS-CoV-2, the virus that causes COVID-19. In three months, this virus has spread to become a pandemic. IMAGE: NIAID-RML
Confirmed cases of COVID-19, the disease caused by the novel coronavirus SARS CoV-2, continue to climb. At the time of publishing, Australia had more than 1000 COVID-19 cases. The global number is well into the hundreds of thousands. And it’s rising.
So how did a virus spread to become a pandemic in just under three months? Before we answer that question, we must look at the basic characteristics of a virus.