Pittman P R, Makuch R S, Mangiafico J A, Cannon T L, Gibbs P H, Peters C J
Division of Medicine, US Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, MD 21702-5011, USA.
Vaccine. 1996 Mar;14(4):337-43. doi: 10.1016/0264-410x(95)00168-z.
The US Army successfully developed a live-attenuated Venezuelan Equine Encephalitis (VEE) vaccine, TC-83, in 1961, and subsequently developed a formalin-inactivated vaccine, C-84, in 1974. Initial evaluation of both vaccines was promising, but no long-term safety and immunogenicity data have been reported. This study is the first analysis of the long-term safety and immunogenicity of TC-83 and C-84. From January 1976 to December 1990, 821 laboratory workers at the USAMRIID were vaccinated with a single 0.5 ml subcutaneous (s.c.) dose of TC-83; 128 were boosted with a single 0.5 ml s.c. dose of C-84. Eighty-two per cent of vaccinees responded to TC-83 with an 80% plaque reduction neutralization titer (PRNT80) of > or = 1:20. Minor side-effects were noted in 23% of vaccinees. No long-term sequelae were recorded. Kaplan-Meier analysis showed a 60% probability of vaccinees maintaining a PRNT80 of > or = 1:20 for 5.5-8 years. C-84 was given to two groups: 76 initial nonresponders to TC-83, Group A, and 52 initial responders to TC-83 whose PRNT80 became < 1:20 over time, Group B. C-84 successfully boosted 76% of Group A and 100% of Group B to a PRNT80 > or = 1:20 Kaplan-Meier analysis showed 100% probability of Group B members maintaining a titer of > or = 1:20 for the duration of follow-up, which, in some cases, exceeded 10 years; while Group A had only a 60% probability of maintaining a titer for 1-2 years. Only minor local reactions to C-84 were noted in 6.3% of vaccinees. We conclude that, although TC-83 is reactogenic, when administered as the primary vaccine and C-84 is administered as a boost, these vaccines provide good long-term immunity and are safe in humans. However, a single dose vaccine that is more immunogenic and less reactogenic is needed.
1961年，美国陆军成功研发出减毒活疫苗——委内瑞拉马脑炎（VEE）疫苗TC - 83，随后于1974年研发出福尔马林灭活疫苗C - 84。对这两种疫苗的初步评估前景良好，但尚未有长期安全性和免疫原性数据的报道。本研究首次对TC - 83和C - 84的长期安全性和免疫原性进行分析。1976年1月至1990年12月期间，美国陆军传染病医学研究所的821名实验室工作人员皮下注射了0.5毫升单剂量的TC - 83；其中128人用0.5毫升单剂量的C - 84进行了加强免疫。82%的接种者对TC - 83有反应，其80%蚀斑减少中和滴度（PRNT80）≥1:20。23%的接种者出现轻微副作用，未记录到长期后遗症。卡普兰 - 迈耶分析显示，接种者在5.5至8年内维持PRNT80≥1:20的概率为60%。C - 84被用于两组人群：A组为76名最初对TC - 83无反应者，B组为52名最初对TC - 83有反应但随时间推移PRNT80降至<1:20者。C - 84成功使A组76%的人和B组100%的人的PRNT80≥1:20。卡普兰 - 迈耶分析显示，B组成员在随访期间维持滴度≥1:20的概率为100%，在某些情况下超过了10年；而A组维持滴度1至2年的概率仅为60%。6.3%的接种者对C - 84仅出现轻微局部反应。我们得出结论，虽然TC - 83有反应原性，但作为初次疫苗接种且C - 84作为加强疫苗接种时，这些疫苗能提供良好的长期免疫力且对人体安全。然而，仍需要一种免疫原性更强且反应原性更低的单剂量疫苗。
