There are seven strains of human coronaviruses:
1. Human coronavirus 229E (HCoV-229E)
2. Human coronavirus OC43 (HCoV-OC43)
3. SARS-CoV
4. Human coronavirus NL63 (HCoV-NL63, New Haven coronavirus)
5. Human coronavirus HKU1
6. Middle East respiratory syndrome coronavirus (MERS-CoV), previously known as novel coronavirus 2012 and HCoV-EMC .
7. Novel coronavirus (2019-nCoV)