Can the supraclavicular nodes react and swell after a vaccine like COVID?

Question

Following my first Moderna covid-19 vaccine I realized that my lymph node below my clavicle (left side same side as I received my vaccine) was swollen and moving up and down my clavicle and it was painful. The swelling went down over time, but I was still able to feel it and on my second dose, a few hours later it started swelling again. To this day, (about 3 months after my second dose) I am still able to feel it under my collarbone, but it is smaller.

Sarah-Yan Chagnon · Accepted Answer

Hello, We have a series of lymph nodes in the clavicles and under the armpits. Since nodes are clusters of white blood cells and vaccines are used to boost/activate our immune system, it can happen that the nodes swell. This is a minor side effect and proof that your immune system is working. Some people will even get this when they get certain infections. Before the vaccine, you had the lymph nodes in the same places, but you may never have realized it because they never swelled. I hope that I have answered your questions, Sarah-Yan Chagnon, pharmacist