This undated electron microscope image made available by the U.S. National Institutes of Health …

This undated electron microscope image made available by the U.S. National Institutes of Health ...

This undated electron microscope image made available by the U.S. National Institutes of Health in February 2020 shows the Novel Coronavirus SARS-CoV-2. Also known as 2019-nCoV, the virus causes COVID-19. (NIAID-RML via AP)