As they are now, though, the travel precautions are far too porous to achieve this desired outcome. For one thing, they do not apply to U.S. citizens and permanent residents. Americans must be able to return home, but we need to acknowledge that if they are coming from southern Africa, they are just as likely as non-residents to carry omicron.

The Biden administration should set up quarantine facilities and require returning Americans to isolate for at least five days and then get a repeat test. This is particularly important given the seemingly high rate of coronavirus positivity among travelers from southern Africa. Of the approximately 600 passengers on two flights from South Africa to the Netherlands who underwent mandatory testing upon arrival, 61 people tested positive for the coronavirus, with at least 13 found due to omicron.