Health officials track safety as COVID-19 vaccines roll out

As COVID-19 vaccinations roll out, health authorities are keeping close watch for any unexpected side effects. Doctors already knew to be on the lookout for severe allergic reactions like an Alaska health worker had after receiving the Pfizer vaccine Tuesday. She is recovering and another worker with an adverse reaction Wednesday has been released from treatment. The cases are a reminder to follow U.S. advice to hang around after the injection just in case of such reactions. More common are flu-like reactions as the immune system revs up. But the government is tracking how recipients fare in several ways, including checkups-by-text in the days after a shot.