Why are they so confident existing vaccines in development will work against the new strain? Isn't that why we get a new flu shot every year, because vaccines don't work against mutated viruses?
Flu changes particularly fast, coronaviruses change much more slowly. However this new covid strain does have some differences in the critical 'spike' bit that vaccines target. They are fairly confident the vaccines will still work. They are doing lab tests to verify. I read somewhere that we'll know more in 2 weeks but I can't remember where I saw that. If the vaccines arent so effective against the new strain, its relatively easy to tweak them (its not like starting from scratch, we know the vaccine approaches work, just need to tweak the payload a little).