Walder R, Bradish C J
J Gen Virol. 1975 Mar;26(3):265-75. doi: 10.1099/0022-1317-26-3-265.
Fourteen strains of VEEV of diverse origin and antigenicity were classified into five virulence categories according to their efficiency of infection and nature of response in mice. Mice of ages up to 30 days represented distinct levels of responsiveness and were suitable for the differentiation of VEEV strains of highest to lowest virulence. Stepwise changes with age of the susceptibility or responsiveness of mice appeared to determined the type of response as predominantly lethal (D), dual or intermediate (DP) or protective (P).
根据14株不同来源和抗原性的委内瑞拉马脑炎病毒（VEEV）在小鼠体内的感染效率和反应性质，将它们分为五个毒力类别。30日龄以下的小鼠表现出不同程度的反应性，适用于区分毒力从高到低的VEEV毒株。小鼠易感性或反应性随年龄的逐步变化似乎决定了主要为致死性（D）、双重或中间性（DP）或保护性（P）的反应类型。
