When somebody catch a flu there are a list of symptoms like fever, aches… but this time I had nothing except the annoying pain of the jab. I realized almost 72

When somebody catch a flu there are a list of symptoms like fever, aches… but this time I had nothing except the annoying pain of the jab. I realized almost 72 later when my heart rate app raised an alarm because I was not training but I was above 135 bpm. I was surprised because I though the immune response of my body was without symptoms, but no, the immune system was doing its job.