Tapa S, Cvjetanović B
Bull World Health Organ. 1975;52(1):75-80.
A controlled field trial was carried out with acetone-dried vaccine on about 35 000 people on the Tongan islands of tongatapu and 'Eua where typhoid fever is endemic. Volunteers were distributed at random into 3 groups, 1 of which received 1 dose of typhoid vaccine and a second 2 doses; the third, a control group, received tetanus toxoid. The population was vaccinated in 1966 and was studied until the end of 1973. Evaluation of the effectiveness of the vaccine was based on cases of typhoid fever that were confirmed by positive blood cultures. Morbidity rates in the 3 groups indicated that the acetone-dried vaccine used was effective and that a single dose of vaccine gave reasonable protection for a short period, but that 2 doses gave greater and longer protection. The results of this trial are compared with those of earlier field and laboratory studies.
在伤寒热流行的汤加塔布岛和埃瓦岛上，对约35000人进行了一项使用丙酮干燥疫苗的对照现场试验。志愿者被随机分为3组，其中一组接种1剂伤寒疫苗，另一组接种2剂；第三组为对照组，接种破伤风类毒素。1966年对该人群进行了疫苗接种，并一直研究到1973年底。疫苗有效性的评估基于血培养呈阳性确诊的伤寒热病例。3组的发病率表明，所使用的丙酮干燥疫苗是有效的，单剂疫苗在短期内能提供合理的保护，但2剂疫苗能提供更大、更持久的保护。将该试验结果与早期现场和实验室研究结果进行了比较。
