virus strain; viral strain
Technical term used in virology, epidemiology, and news reports to refer to a specific genetic variant of a virus.
The effectiveness of the vaccine against the new virus strain is being investigated.
This viral strain is highly contagious.
Compound of ウイルス (virus) and 株 (stock, strain). The use of 株 for biological strains is a semantic extension from its original meaning of 'stock' or 'stump'.