A Covid-19 vaccine may cause unpleasant side effects. People should be prepared, scientists say.

A Covid-19 vaccine may cause unpleasant side effects. People should be prepared, scientists say.

Pfizer is expected to seek federal permission to release its Covid-19 vaccine by the end of November, a move that holds promise for quelling the pandemic but also sets up a tight time frame to make sure consumers understand what it will mean to get the shots.

By Miki