Can he take Covid Vaccine today itself?

He was detected with Kidney symptoms for last 5-6years and consuming medications for it. Till January 2021 he was consuming only 5mg of Wysolone and was completely fit. But in January 2021 doctor advised him to leave the medication and see. Because of which he developed a lapse and developed Kidney symptoms again. So from then he is consuming Wysolone tablets regularly for nearly 4 months with increasing amount of concentration.Initially he started with 60mg of Wysolone in January and currently consuming Wysolone 20mg daily which is a steriod. Now his personal doctor is not allowing him to take vaccination immediately and asking him to wait for another 1month. But we family members are worried about Covid situation in our locality very much. So I want to ask on behalf of my father whether it is harmful to take vaccination for him as soon as possible? Thanking you sir/madam in advance.