Yes! Get your mammogram — especially if the pandemic threw off your schedule. But be sure to schedule it with your COVID vaccine in mind. The COVID-19 vaccine activates your immune system, which can enlarge your lymph nodes, particularly those closest to the injection site — under the armpit on the side you receive your injection. The nodes are small lumps and they will appear on a mammogram. Swollen lymph nodes under one arm can be a rare sign of breast cancer. To avoid the possibility of the need for a second screening to verify the temporary swelling is related to the vaccine, we encourage you to schedule your mammogram before your first dose or four or more weeks after your second. For more information about the COVID-19 vaccine and mammograms, visit the FAQ section of our COVID-19 site, here.