Effect of Beta-Propiolactone on Complement-Fixing Antigens of St. Louis Encephalitis Virus.

Inactivated Eastern Equine Encephalomyelitis Vaccines Prepared in Monolayer and Concentrated Suspension Chick Embryo Cultures

“…Previous reports (7,9) have shown that BPLinactivated arboviruses may have increased HA titers as a result of BPL treatment. Furthermore, it has been shown in this and other laboratories (6,20) that formalin-inactivated arboviruses lose all of their HA activity within a few hours after treatment ( Table 1) preparations were sedimented in linear, 10 to 40% sucrose density gradients.…”

“…DISCUSSION A comparative study was made of the immunogenic properties of EEE vaccines inactivated by three different methods, with virus grown under two different sets of conditions. The investigation attempted to answer two basic questions: (i) does concentrated suspension CEC serve as a better source of EEE virus production than monolayer CEC (11,13), and (ii) do the methods of virus inactivation have any effect on the immunogenicity of inactivated vaccines (6,7,11) ?…”