Increased insulin requirement even months after COVID-19 infection

A 28 year old male, type 1 diabetic usually requires an average of 110 units of insulin daily. However, since getting Covid-19 infection three months ago, his requirements have gone up to nearly double. Hba1c is also slightly increased. Fortunately, he has never suffered from complications of hyperglycaemia as he is very well educated and understands how to control his blood glucose quite well. This is not his first Covid-19 infection, he has had two previous infections and both times his insulin requirements went back to normal within 2-3 weeks. Is there anything that can be done to help his control?