Medical experts answer questions about the new COVID-19 variants: what they are, what they do and how to protect against them. Sign up for COVID-19 text alerts at newsday.com/text. Panelists include David Hirschwerk, M.D., Attending-Infectious Diseases, Interim Chair of Medicine Donald & Barbara Zucker School of Medicine at Hofstra/Northwell; and Alan Bulbin, M.D., Director of Infectious Diseases and Antimicrobial Stewardship, St. Francis Hospital.