The C.D.C. Has New Covid Guidelines. This Is What It Got Wrong.

For nearly two years, American officials have changed recommendations on how to manage the coronavirus. On Monday we got one of the biggest shifts yet: Infected people, who had long been told to isolate for at least 10 days, now have to isolate for only five days if they feel fine, regardless of vaccination status. On one level, this decision by the Centers for Disease Control and Prevention is a welcome nod to science and practicality because many people aren’t infectious for such a long period.

But the change doesn’t grapple effectively with the reality that the fully vaccinated and boostered and the unvaccinated are living in two different worlds. The C.D.C. guidelines still rely on a mostly one-size-fits-all approach and ignore the use of antigen testing to make distinctions between the relative safety and danger of both groups.

When the pandemic began, there were no vaccines, so we all lived in a world where everyone was at the same high risk. The C.D.C. therefore recommended that people who became infected shelter in place for 10 days because evidence pointed to the fact that they could be infectious for quite some time. The C.D.C. also argued that those who were credibly exposed but not yet sick quarantine for 14 days, because it could take that long for them to become infected and infectious.