SARS-CoV-2 articles from across Nature Portfolio SARS-CoV-2 is a positive-sense single-stranded RNA virus. It is contagious in humans and is the cause of the coronavirus disease 2019 (COVID-19).

A 3-2-1 buydown mortgage offers borrowers a three-year break from high interest rates. However, they must be ready to pay the original rate from the fourth year onward.