Yes, it is generally safe for your child to receive the Varicella vaccine one day after completing an antibiotic course. Antibiotics such as Hifen 50 DT (Cefixime) do not usually reduce the effectiveness of the Varicella vaccine or cause harmful interactions with it. Doctors usually avoid vaccination only if the child is seriously unwell, has a high fever, or is recovering from a severe infection. If your child was active, feeding well, and had no significant fever at the time of vaccination, there is usually no cause for concern. After the vaccine, your child may develop a mild fever, slight rash, or soreness at the injection site, which are common and temporary side effects. Continue to monitor your child, keep him well hydrated, and consult your paediatrician if there is persistent high fever, breathing difficulty, severe rash, or unusual drowsiness.