It hasn't been eradicated..it just causes far fewer infections due to increased herd immunity from a combination of vaccination, natural exposure and other new strains of influenza becoming more 'fit' i.e. competitive.

But yes, if we could have cases down the low hundreds, active containment is still formally possible. Believe it or not, that window of opportunity is now (if we believe lack of cases in countries reporting no or few cases). Which is why lax attitudes to containment are really bizarre. Otherwise, as with H1N1, we may need to see a global peak first (hundreds of millions++ cases), then decline, and then try to eradicate. Scenario 3 is that this just fizzles in the background without containment, for reasons that aren't well understood. MERS is like that, but it's a very different beast to COVID-19.

tb