They possibly thought based on previous outbreaks in Asian countries that people would see the severity of the problem and that it could be contained enough (an

They possibly thought based on previous outbreaks in Asian countries that people would see the severity of the problem and that it could be contained enough (and with that likelihood of mutations lowered) until vaccination efforts have reached their threshold. The probably didn't expect that multiple big countries would just let people go about their daily lives normally for a long time and spread the virus in that proportion.