Even before President Donald Trump announced that he intends to temporarily suspend immigration to the U.S. because of Covid-19, it was becoming clear that the effect of the virus on migration would be powerful, long-lasting and unfortunate. Many countries besides the U.S. have already shuttered or severely limited entry from foreigners – and many of those restrictions will not be so easily removed when the worst of the pandemic has passed.There is no guarantee that a good vaccine will be ready quickly, even within two years. There is still no vaccine, for instance, for the common cold or HIV-AIDS. Even if the U.S. has Covid-19 under control, there might be persistent if small pockets of Covid-19 in other countries, including populous, poor countries such as India, Pakistan and Nigeria. The U.S. may be reluctant to take new migrants from those parts of the world.
