Effect of Formalin, β-Propiolactone, Merthiolate, and Ultraviolet Light Upon Influenza Virus Infectivity, Chicken Cell Agglutination, Hemagglutination, and Antigenicity

Four strains of influenza virus were treated with Formalin, Merthiolate, Merthiolate and Formalin, ultraviolet light, and β-propiolactone (BPL) for 18, 48, and 72 hr. Infectivity, chicken cell agglutination (CCA), hemagglutination (HA), and antigenicity determinations were made. Except for Merthiolate, each method of inactivation was equally effective in reducing infectivity. Loss of infectivity was related to length of treatment. CCA determinations were higher for all treated groups except for BPL-treated samples; these had lower determinations. BPL treatment also lowered the HA titer. Antigenicity was lessened by BPL treatment and by Merthiolate and Formalin treatment. Generally, the length of inactivation up to 72 hr did not affect CCA, HA, or antigenicity determinations. For the most part, there was no significant differences in the reactivity of the four strains.