The agreement does allow for that.
But I don't think that the situation calls for a full throttled shut everything down, oj! wie is mir, panic.
Since I travelled to Asia 3 1/2 weeks ago I was quite concerned and very abreast with valid information. So I mostly referred to the one reasonable source[1].
In no instance have they suggested any bans on travel or trade. And frankly, I put more stock into the opinion of the WHO than, say, Mike Pence'.
In addition I'm travelling from a country were the risk of infection is lower than if I travelled from neighboring Italy.
That's not to say that I'm blasé about the issue. If I would feel any slight symtoms I'd immediately contact my doc, relay my travel history and do whatever is required. Legally and morally.
Full throttle panic in the line of The end is nigh, shut down all borders! is, if anything, extremely counter productive.
[1] https://www.who.int/
