日本語 
変異したウイルス
英語での表現＆単語の場合は品詞
mutant virus
mutant strain[variant] of the virus
mutant strain[variant] of the virus
英語例文＆出典
Christmas is cancelled by surging mutant virus (the Sunday Times見出し)
Europe moves to isolate UK as mutant virus ruins christmas.
By talking up the mutant virus and talking down their own incompetence the govt has handed every neighbouring country the right to shut down travel and supply.
...the PM was handed alarming new evidence of the virulence of a mutant strain of the virus
Government’s scaremongering about a “mutant” variant of the virus, intended to justify Tier 4 restrictions, is now being taken literally by our trading partners.
Europe moves to isolate UK as mutant virus ruins christmas.
By talking up the mutant virus and talking down their own incompetence the govt has handed every neighbouring country the right to shut down travel and supply.
...the PM was handed alarming new evidence of the virulence of a mutant strain of the virus
Government’s scaremongering about a “mutant” variant of the virus, intended to justify Tier 4 restrictions, is now being taken literally by our trading partners.
補足・特記事項など
See also 変異株、変異種: variant