Keith Roach, M.D., syndicated columnist

DEAR DR. ROACH: Can a skin test show if a person will react poorly to a COVID-19 vaccine? I’ve had serious allergic reactions to so many meds! I’m too afraid to risk getting the shot. Can it be given in half doses to lessen potential adverse effects? I won’t get the shot without some assurance. — M.L.

ANSWER: The risk of a serious allergic response to a COVID-19 vaccine is small, approximately five people per million. The vast majority of these occurred in people with previous serious allergic reactions and occurred within 30 minutes of the vaccine. People with a history of severe allergic reaction, such as anaphylaxis, to any vaccine should be referred to an allergist for evaluation prior to vaccination. The allergist may do testing, such as skin testing, prior to giving the vaccine. The vaccine should be given where trained experts and appropriate equipment is immediately available in the unlikely case of a severe reaction. People with other kinds of allergic responses to foods or medicines, such as a rash to penicillin, are probably at no higher risk than the general population to get a severe reaction to the COVID-19 vaccine. You should definitely speak with your physician about your personal risk. Most people will be able to get the vaccine with no trouble.

EDITOR’S NOTE: Readers may email questions to ToYourGoodHealth@med.cornell.edu or mail questions to P.O. Box 536475, Orlando, FL 32853-6475.