De Swardt R, Ijsselmuiden C B, Johnson S
Department of Community Health, University of the Witwatersrand, Johannesburg.
S Afr Med J. 1990 Dec 15;78(12):726-8.
Seroprevalence was used to evaluate the vaccination programme in the Elim health ward of Gazankulu. Antibodies to measles and polio were measured in 1-6-year-old children together with vaccination status. In 224 children studied using a cluster sampling technique, vaccine coverage was found to be 86% for measles and over 90% for polio and diphtheria, pertussis and tetanus. It was difficult to determine vaccine failure rates accurately; 21% of children were seronegative after having received measles vaccine, 32% who had apparently not been vaccinated had antibodies, while a total of 27% had no measles antibodies. Thirty-nine per cent of children failed to demonstrate antibodies to all 3 types of poliovirus after having received 3 doses of oral polio vaccine, 94% had immunity against type 2, and 76% and 74% were immune to types 1 and 3, respectively. Reasons for diminished effectiveness of vaccination programmes are cited; in this study it was probably due to decreased vaccine efficacy related to inadequacies in the cold-chain. Recommendations are that seroprevalence studies are useful, but only after vaccine coverage and the cold-chain have been optimised.
血清阳性率被用于评估加赞库卢省埃利姆健康区的疫苗接种计划。对1至6岁儿童的麻疹和脊髓灰质炎抗体以及疫苗接种状况进行了检测。在采用整群抽样技术研究的224名儿童中，麻疹疫苗接种覆盖率为86%，脊髓灰质炎、白喉、百日咳和破伤风疫苗接种覆盖率超过90%。准确确定疫苗失败率很困难；21%的儿童在接种麻疹疫苗后血清学检测呈阴性，32%显然未接种疫苗的儿童有抗体，而总计27%的儿童没有麻疹抗体。39%的儿童在接种3剂口服脊髓灰质炎疫苗后未能对所有3种脊髓灰质炎病毒型别产生抗体，94%的儿童对2型有免疫力，76%和74%的儿童分别对1型和3型有免疫力。文中列举了疫苗接种计划效果降低的原因；在本研究中，可能是由于冷链不足导致疫苗效力下降。建议血清阳性率研究是有用的，但前提是疫苗接种覆盖率和冷链已得到优化。
