Arm swelling post vaccine. On that side?

It is normal following vaccination. The vaccine is given in the muscle so some soreness and pain is to be expected. The most common side effects following COVID-19 vaccines are fatigue, a fever, headaches, body aches, chills, nausea, diarrhea, and pain at the site of injection, according to the World Health Organization. These may last from a few days to a week and are mostly self limiting. Take medication as prescribed by your doctor and rest. You can keep a clean wet cloth or icepack on the affected area to reduce pain. Consult your doctor if redness, tenderness, or swelling of the hand worsens. Do not rub the injection site. Drink plenty of fluids to stay hydrated. Avoid doing strenuous activities for at least 3-4 days after getting the vaccine. It is safer to avoid alcohol and smoking for a few days. The vaccine does not fully prevent infection by the COVID-19 virus. However it drastically reduces the chances of severe life threatening consequences and death due to COVID-19.

this maybe vaccine reaction  take levocetirizin daily and calpol 500 eight hrly for 3 days

Its very common sideeffect of Vaccine.It can last upto 2-3 days post vaccination. Take Tab Dolo 650 to relieve pain

Apply icepack on injection site