The sequence of the current strain exhibits some drift from the 1976 version. Lower mortality but easier transmission may be the result.
Something that’s got 90+% mortality but isn’t easy to transmit is a very different bug from something that’s got 30+% mortality but is much more easily transmissible.
The former burns itself out. The latter is a pandemic.
>> Lower mortality but easier transmission <<
Definitely. That’s the evolutionary mechanism at work. If the virus “wants” to survive, it’s got to stop killing almost everybody it infects. It needs to have victims who are walking around and infecting others, not corpses buried in the ground.
Then as time goes by, the virus will tend to get even weaker, until ordinary public health and sanitary measures can keep it under control, at least in developed economies like those of the USA and Europe.
Bottom line:
Such a virus may never disappear entirely, and there may be occasional bad outbreaks, but it is very unlikely to become the “monster” pandemic of sci-fi movies.