I need help to find the suitable formula (nested if does not work).

I have three worksheets with names and id numbers.
On the May worksheet, employees underwent medicals.
On the June worksheet, all the employees are registered again, but the ones that did the medical in May, do not need a medical in June and the same for July (the medical is valid for four months).
I need to work on the June and July worksheets, compare the identification numbers of the employees and if they went for the medical in May, have a column that state "Operational", but if they did not complete the Medical in May, the statement "Medical" must appear.
My formula: =if(and(B1=May!$B$B6:$B$12,June!$B$B6:$B$12,"Operational","No Medical") does not work, because it only reads the one value in B6 and ignores the rest.
Thanking you for any help in anticipation
Marleine