common moorhen coronavirus hku21 common moorhen coronavirus hku21 common moorhen coronavirus hku21 is a species of coronavirus in the genus deltacoronavirus. common moorhen coronavirus hku21 virus classification (unranked): virus realm: riboviria kingdom: orthornavirae phylum: pisuviricota class: pisoniviricetes order: nidovirales family: coronaviridae genus: deltacoronavirus subgenus: buldecovirus species: common moorhen coronavirus hku21