ALBANY, N.Y. (NEWS10) — Most women get a yearly mammogram after the age of 40. This year, they need to be aware that the COVID-19 vaccine may interfere with their results. 

“During vaccine trials they found both men and women were palpating, feeling lumps in their armpits or same side where they had vaccine,” explained Dr. Kirsten Cestaro, a radiologist with St. Peter’s Breast Center. She says both the Pfizer and Moderna vaccine come with this possible side effect of enlarged lymph node following the first and second shot. 

“This is harmless, temporary enlargement of lymph nodes. It’s actually a good sign; it means the vaccine is working and body is mounting an immune response. That’s positive,” she added. 

But it’s not something you want to pop up in your mammogram results.

“When we see enlarged lymph nodes, that can be a secondary sign of breast cancer,” Dr. Cestaro explained, which can result in a false positive. 

“A woman’s main priority should be getting the vaccine. Don’t delay getting the vaccine because you’re worried about your screening mammogram interfering with it,” she added. 

Dr. Cestaro is advising patients to reschedule their mammogram four to six weeks after the second dose. She says, by then, the lymph nodes shrink back to normal.