I note the recent passing of Maurice Hilleman on 11 April 2005. Dr. Hilleman was a giant in the field of vaccines. Working at Merck & Co., he developed 8 of the 14 commonly used vaccines: measles, mumps, hepatitis A, hepatitis B, chickenpox, meningitis, pneumonia, and Haemophilus. Among his other achievements, he found that SV40 was a contaminant of early poliovirus vaccines.
The official Merck announcement can be found here.