根据疫苗制造商的推荐， 辉瑞疫苗2剂应该3周， 而莫得那则为4周。
但目前政府希望2剂间隔时间拉长到8周， 这样可以给更多人的机会注射机会， 同时也强调间隔时间延长到8周不会影响疫苗的效果。
这是美国CDC今年2月初的推荐
“The second dose should be administered as close to the recommended interval as possible,” according to guidance updated Thursday. But if it is not feasible to get the second dose in that period, the CDC says a second shot may be scheduled “up to 6 weeks (42 days)” after the first shot.“