A strain (of a virus, bacterium, etc.) that has acquired genetic mutations; often refers to variants whose properties (infectivity, severity) differ from the original strain.
新しい変異株が報告され、専門家が影響を調べている。
A new variant strain has been reported, and experts are investigating its impact.
ワクチンは元の株に対して開発されたが、変異株に対する効果を評価する必要がある。
Vaccines were developed against the original strain, but it's necessary to assess their effectiveness against variant strains.
研究室で変異株を分離して、増殖速度や薬剤感受性を調べた。
They isolated a variant strain in the lab and examined its growth rate and drug susceptibility.
市中で優勢になった変異株の登場が流行の拡大につながった。
The emergence of a variant strain that became dominant in the community led to an expansion of the outbreak.