As they tell us they cannot stop the virus from entering the country, they have demonstrated the impossibility in stopping a virus if you keep the borders open. Many things have been learned from this episode. One, is that you have about a month advanced notice, so if you do not have a countering agent in that time you could die if it were a dangerous virus. Second, permitted free travel spreads all disease without impediment. Hence, thirdly, if countries do not take action to limit the cesspools from which these diseases arise, they are endangering all other countries.
Another possibly troublesome problem we could have learned also from Africa, is that some populations intentionally spread diseases if they perceive it to be the case that the virus was planted on them. This perception is often the case. The Africans, the Chinese, and the Mexicans all thought the US planted a virus in their countries.
If the US gets the virus in a big way, it will probably start in S California.