The Production of Fever by Influenzal Viruses

The effect of treating rabbits with materials which destroy the cell receptors for influenzal viruses upon the ability of these animals to respond with fever to injection of the PR8 and Lee strains of influenza virus and Newcastle disease virus (NDV) is described. In general, both cholera vibrio and Cl. welchii filtrates produced diminution of febrile responses. The effect of sodium periodate upon the pyrogenic reaction was not significant. Near-lethal amounts of these materials were necessary to demonstrate their protective effects against virus challenge. In order to rule out general debility as a factor in lessening the fever, it was shown that the ability of animals to respond to the pyrogenic effect of typhoid vaccine was unimpaired by injection of receptor-destroying substances. The substances tested were more effective in abolishing the febrile response to PR8 virus than to Lee virus or NDV. This finding is compatible with previous studies of the protective effect exerted by homologous and heterologous viruses. These findings give support to the hypothesis that union of virus and host receptor substance plays a part in the production of fever by these viruses.