Pain, redness, swelling, a hard lump, bruising or itching around the injection site are the common side effects of this vaccine. Since this swelling has persisted for more than 5 days now it definitely needs treatment. It can possibly be a side effect of the vaccine.Antiinflammatory drugs may be needed to reduce the swelling. Only external examination can confirm whether there is any infective focus which may need antibiotics. It is best to discuss your concerns with your doctor. Do keep us posted on how he is doing.