Pyrogenicity of human adenoviruses

High doses (>1·56×107 p.f.u.) of purified preparations of human adenovirus types 3, 5 and 8 exhibited definite pyrogenic activity when injected intravenously into rabbits. Complete pyrogenic tolerance was obtained not only with homologous types but also with heterologous types of adenovirus. No pyrogenic cross-tolerance was observed between each of these three adenovirus types and paramyxovirus pyrogen or bacterial lipopolysaccharide. Adenovirus pyrogenicity was retained after UV-inactivation, whereas it was inactivated by heating at 56 °C for 30 min. Adenovirus pyrogenicity was not neutralized by mixing with homologous type-specific antiserum but non-pyrogenic doses (107 p.f.u.) of adenovirus types 3, 5 and 8 became highly pyrogenic in the presence of type-specific antibodies at the optimal virus:antibody ratio. This enhanced pyrogenicity depended upon the virus–antibody complex. From these results, it is probable that the pyrogenic activity of the virus–antibody complex, rather than the pyrogenic activity of the virions, is the main contributor to fever in adenovirus infection under actual physiological conditions.