It's almost certainly created by someone in a lab, the evidence against it being a naturally occurring virus is pilling up by the day.

If you ever played Plague Inc, apparently the best way to 'win' was to have a virus initially show small symptoms to spread, then mutate into something terrible.

This was made in a lab so that mentality would apply. We think this isn't that bad. It's because we can't think more than a move in front of our faces.

This thing is out and spreading, of course the first iteration is going to be mild.

Wait a year.