Seven Coronaviruses

About Seven Coronaviruses

Seven coronaviruses are known to infect humans. Four cause common colds: HCoV 229E identified in 1965, HCoV OC43 in 1967, HCoV NL63 in 2004, and HCoV HKU1 in 2005. These four circulate seasonally and cause approximately 15 to 30 percent of common colds. The three pathogenic coronaviruses are SARS CoV identified in 2003, MERS CoV in 2012, and SARS CoV 2 in 2019. The SARS outbreak killed 774 people before being contained. MERS had killed nearly 900 people by 2021, and as of 2024 more than 7 million COVID 19 deaths had been reported. Coronaviruses are RNA viruses with the largest genomes among RNA viruses, approximately 30,000 bases. The viruses likely originated in bats. The frequency of coronavirus emergence is increasing, driven by human encroachment on wildlife habitats, live animal markets, and global connectivity. Some experts have argued that the emergence of SARS in 2003 was an early warning that went insufficiently heeded.