2 sentences

1. 通过接种牛痘，人类成功消灭了天花。

   tōng​guò jiē​zhòng niú dòu, rén​lèi chéng​gōng xiāo​miè le tiān​huā.

   Through cowpox vaccination, humanity successfully eradicated smallpox.

   Source: Dong Chinese Dictionary

2. 由于采取了有效的防疫措施，天花已被人类消灭。

   yóu​yú cǎi​qǔ le yǒu​xiào de fáng​yì cuò​shī, tiān​huā yǐ bèi rén​lèi xiāo​miè.

   Due to effective epidemic prevention measures, smallpox has been eradicated.

   Source: Dong Chinese Dictionary