If a vaccinated person is exposed to COVID but doesn't get sick, does that affect that person's immunity? Is weekly testing for unvaccinated coworkers really sufficient to protect everyone? Are any new variants keeping you up at night? Should people switch vaccines for their booster doses? Amesh Adalja of the Johns Hopkins Center for Health Security and Josh Sharfstein address COVID-19 questions submitted to publichealthquestion@jhu.edu.
