The billionaire philanthropist also described access to testing in the US as 'chaotic' but said he was hopeful that a vaccine could be created within the speculated one to two year time-frame.

'I wish I could say that we're halfway through, but I don't think so. It takes time to make a vaccine... There's a lot about the disease we don't know about. It's going to be a while before things go back to normal,' he told NBC's Today on Friday. 

'Usually a vaccine takes over five years... The best scientists are working hard on this, and I'm hopeful. In fact, in the last few weeks I've seen signs that we may get to the optimistic side of that time projection.'

The Microsoft founder said he feared many states would reopen too quickly and that people would become complacent, which could potentially see a surge in infections. 

He said he hopes a second wave of infections predicted in the Fall won't be as bad as what is currently being experienced now. 

'If we're still being careful about social contact, if we've got the testing capacity up, I'm hopeful that the fall will not be nearly as bad as this first peak,' he said.