People who have received the Pfizer-BioNTech or Moderna coronavirus vaccines can skip the two-week quarantine if they are exposed to someone infected with COVID-19, the Centers for Disease Control and Prevention announced in new guidance Wednesday. Some caveats remain: The vaccinated people must have been injected with both doses of the vaccine, and two weeks must have elapsed between the second shot and the exposure so that the preventative is in full effect. In the unlikely event a vaccinated person begins to show symptoms, they should still quarantine, and they should still wear masks and avoid crowded spaces. The new guidance offers welcome information for the vaccinated, who were previously advised not to change their precautions against COVID-19 at all.