4 sentences

1. 蜘蛛毒液发生了变异。

   zhī​zhū dú​yè fā​shēng le biàn​yì.

   The spider venom has mutated.

   Source: OpenSubtitles

2. 这种病毒发生了变异。

   zhè zhǒng bìng​dú fā​shēng le biàn​yì.

   The virus has mutated.

   Source: Dong Chinese Dictionary

3. 病毒开始变异了。

   bìng​dú kāi​shǐ biàn​yì le.

   The virus is starting to mutate.

   Source: Tatoeba

4. 这种新型变异株的传染力比之前更强。

   zhè zhǒng xīn​xíng biàn​yì zhū de chuán​rǎn​lì bǐ zhī​qián gèng qiáng.

   The infectivity of this new variant strain is even stronger than before.

   Source: Dong Chinese Dictionary