The world may never eradicate coronavirus, but it can get it under control.
The world is able to get coronavirus under control.
The world may never eradicate coronavirus, but it could get it under control.
The world is able to get coronavirus under control.
[The implication 'if it decides it wants to' is somewhat stronger. It's a subtle and vague difference, but there's a greater sense of uncertainty and 'conditional on other circumstances' implied with 'could'. This is often particularly clear when spoken, for instance "I guess they could get it under control?" spoken with a rising/questioning inflection would express strong doubt that they would get it under control. But it's also possible to say 'the world could get it under control any time they want to'], which would express complete certainty that the world has the ability to control coronavirus. The precise meaning is therefore highly dependent on context.
The world may never eradicate coronavirus, but it might get it under control.
It is unclear whether the world is able, or will, get the coronavirus under control, or whether the circumstances exist to get it under control. However it is also far from clear that the world won't get it under control.