B-cell or T-cell immunity?

The influenza virus behaves unpredictably and can cause devastating pandemics. Nearly 50 years after its first isolation it is probably the most infectious agent known that we cannot yet control. Why? The answer lies in the virus's unique capacity to alter antigenically and in the inability of the host's immune system to respond satisfactorily to the vaccines currently available. What follows is a record, prepared exclusively for Immunology Today, of a conference held in Oxford on March 21–24 this year, to discuss problems relating to protection against influenza.