Distillate of Immunization  

I    cures  8 disease counters ( 2x4), no req. level 
II   cures 12 disease counters ( 3x4), req. level 5 
III  cures 16 disease counters ( 4x4), req. level 10 
IV   cures 20 disease counters ( 5x4), req. level 15 
V    cures 24 disease counters ( 6x4), req. level 20 
VI   cures 28 disease counters ( 7x4), req. level 25 
VII  cures 32 disease counters ( 8x4), req. level 35 
VIII cures 36 disease counters ( 9x4), req. level 45 
IX   cures 40 disease counters (10x4), req. level 55 
X    cures 44 disease counters (11x4), req. level 65