Hi
Give him food which will boost his immunity.
vegetables and fruits rich in Beta carotene, Ascorbic acid & other essential vitamins. Certain foods like mushrooms, tomato, bell pepper and green vegetables like broccoli, spinach are also good options to build resilience in the body against infections.
Ginger. Lemon, green tea you can include
U can give meat,fish and chicken.
Plan a well balanced meal and plus with all this what I mentioned.
Plus
vitamin c supplements 1000mg per day should be
sugar free and 3lts off water in a day.
Health Tips
Take care and get well soon.