My hunch is that herd immunity is holding up in America.
所有跟帖:
• That‘s right. I think mRNA vaccines are more effective. -妖妖靈- ♀ (0 bytes) () 01/05/2023 postreply 14:25:27
• The 1918 flu pandemic provides a good rear view. -renqiulan- ♂ (0 bytes) () 01/05/2023 postreply 15:52:21