“这次活动主要是为了第二次未接种或接种无效果的儿童增强免疫”，他说。

"It's a catch-up campaign to boost the levels of immunity among children who may have missed the second dose, or in whom one of the doses was not effective," he said.

youdao

“这次活动主要是为了第二次未接种或接种无效果的儿童增强免疫”，他说。

"It's a catch-up campaign to boost the levels of immunity among children who may have missed the second dose, or in whom one of the doses was not effective," he said.

youdao