Here's a hint: more than one, fewer than three.

提示：多于一个，少于三个。

youdao

Could fewer than three vaccinations provide adequate protection?

少于3种的免疫接种可以提供足够的保护吗？

youdao

Could fewer than three vaccinations provide adequate protection?

少于3种的免疫接种可以提供足够的保护吗？

youdao