xǔ duō / guó jiā / zhèng zài / nǔ lì / tōng guò / yì miáo / jiē zhòng / shí xiàn / qún tǐ miǎn yì

许多国家正在努力通过疫苗接种实现群体免疫。

Many countries are working hard to achieve herd immunity through vaccination.