Many key concepts concerning the nature of immunity have originated from the very practical need to control virus infections.

This year, 1996, has been designated the 'Year of the Vaccine,' commemorating the 200th anniversary of Edward Jenner's vaccination of James Phipps with cowpox virus and subsequent challenge with smallpox virus. Insight into the nature of viruses, and how viruses interact with mammalian cells, has evolved since the turn of the century.

The need to deal with pathogens has driven the evolution of the vertebrate immune system, so it should not be surprising that experiments with infectious agents have often illuminated key elements of the underlying mechanisms.

My mother was a very talented pianist, and she was a music teacher who hated to teach music, actually, but she loved to play, so I was brought up with Chopin, Debussy and Mozart.

We generated the portion that we think was important for immunity. We never manipulated the actual H5N1 virus ourselves, so it is safe to generate this kind of vaccine.

I share Alfred Nobel's conviction that war is the greatest of all human disasters. Infectious disease runs a good second.