Hello, it's about slowing the rate of transmission, not stopping it, because that can't be done at this point, but we want to delay the peak until summer because we don't want to have this and the flu at the same time, besides at this point it would be irresponsible from the US NOT to close their border with Mexico, seeing as how US has a lot more cases then Mexico ATM, we need to contain the spread both ways otherwise there will be backflow and even if US manages to contain it's outbreak repositories of the virus will be created in neighboring countries and create new outbreak in time.