Journal of Experimental Medicine

After infection w i t h unrelated viruses such as paramyxoviruses, orthomyxoviruses, poxviruses, and rhabdoviruses (1) mice generate cytolyt ic Τ lymphocytes ( C T L) 1 that possess selective specificity for the sensitizing virus. However, after infection w i t h different subtypes o f serologically distinct influenza A viruses (2) at least more than one popula t ion o f C T L can be demonstrated. Both cross-reactive and subtype-specific