Bolotovski V M, Grabowsky M, Clements C J, Albrecht P, Brenner E R, Zargaryantzs A I, Litvinov S K, Mikheyeva I V
Central Research Institute of Epidemiology, Moscow, Russia.
Int J Epidemiol. 1994 Oct;23(5):1069-77. doi: 10.1093/ije/23.5.1069.
Measles kills more than 1 million infants per year and is particularly lethal in infants < 1 year old in developing countries. Recent reports have suggested that measles vaccines of different strains and titre differ in their immunogenicity in young infants. We sought to identify strains and titres of measles vaccines which would be effective in 6 and 9 month old infants.
We conducted a randomized trial of AIK-C, Edmonston-Zagreb (EZ), Leningrad-16 and Schwarz strains of measles vaccine at different titres in 1202 6 month old and 1250 9 month old infants. Antibody levels were measured by haemagglutination inhibition assay. Seroconversion was defined as a change from seronegative to seropositive or a fourfold rise in titre above the expected level after antibody decay (assumed antibody half-life = 6 weeks). Chi-square tests were used to compare seroconversion rates and rates of adverse reactions among the groups. Comparison of geometric mean titres (GMT) was done by the Student's t-test.
No severe or unusual adverse reactions occurred during the 6 weeks after vaccination. All strains induced high seroconversion rates in 9 month old infants. In 6 month olds, medium- and standard-titre AIK-C induced the highest rates of seroconversion. Antibody titres at 6 weeks after vaccination were highest in recipients of Schwartz vaccine and lowest for EZ vaccine recipients.
Standard-titre AIK-C may be more effective than other measles vaccine strains for early measles immunization and should be evaluated further for efficacy, long-term immunogenicity, and long-term safety.
麻疹每年导致超过100万婴儿死亡，在发展中国家，1岁以下婴儿中尤其致命。最近的报告表明，不同毒株和滴度的麻疹疫苗在幼儿中的免疫原性有所不同。我们试图确定对6个月和9个月大婴儿有效的麻疹疫苗毒株和滴度。
我们对1202名6个月大婴儿和1250名9个月大婴儿进行了一项随机试验，使用不同滴度的AIK-C、埃德蒙斯顿-萨格勒布（EZ）、列宁格勒-16和施瓦茨毒株的麻疹疫苗。通过血凝抑制试验测量抗体水平。血清转化定义为从血清阴性变为血清阳性，或在抗体衰减后（假设抗体半衰期=6周）滴度高于预期水平四倍的升高。使用卡方检验比较各组之间的血清转化率和不良反应发生率。通过学生t检验比较几何平均滴度（GMT）。
接种疫苗后6周内未发生严重或异常不良反应。所有毒株在9个月大婴儿中诱导出高血清转化率。在6个月大婴儿中，中滴度和标准滴度的AIK-C诱导出最高的血清转化率。接种疫苗后6周时，施瓦茨疫苗接种者的抗体滴度最高，EZ疫苗接种者最低。
标准滴度AIK-C在早期麻疹免疫方面可能比其他麻疹疫苗毒株更有效，应进一步评估其疗效、长期免疫原性和长期安全性。
