Our bodies' immune system produce a variety of mild symptoms when introduced to a vaccine. It's a sign our body is producing antibodies to fight the virus. These symptoms are often extremely mild and can include: Sore arm, swollen lymph nodes, chills or fever fatigue, body aches, or feeling run down, joint pain, headache, nausea, vomiting or diarrhea. These symptoms normally resolve within 1-2 days.