We have a lot to learn from countries that initially seemed to have the outbreak under control but are now beginning to see a resurgence. Singapore and Hong Kong are already experiencing new outbreaks of Covid-19, possibly due to travelers returning from other parts of the world. In Hokkaido, Japan, strict control strategies have been re-introduced because of a new surge of Covid-19.
Other factors may be at play, as some scientists now believe the disease could be far more infectious than previously thought. The original understanding was that every person infected with the virus could pass the infection on to another two to three people; now, that number might be more than five secondary infections.