Successfully developing vaccines within a year of the Covid-19 pandemic outbreak was an unprecedented achievement, but their rollout to low- and middle-income countries continues to drag.
在新冠疫情爆发的一年内成功开发疫苗是一项前所未有的成就，但在中低收入国家推广疫苗仍然受阻。
您已阅读3%（232字），剩余97%（7359字）包含更多重要信息，订阅以继续探索完整内容，并享受更多专属服务。