Sensitization to the influenza virus in a combined experimental infection

Two groups of guinea-pigs were infected with live attenuated A2 virus in nasal drops and with simultaneous and subsequent administration of virus vaccine and live Haemophilus influenzae. In combined infection the late skin reactions to virus antigens proved to be significantly higher. H. influenzae infection stimulated the production of antiviral homocytotropic antibodies in guinea-pigs probably due to the adjuvant effect of the capsulated bacteria.