新冠病毒疫苗三期试验中期揭盲条件及保护率研究

Study on Uncovering Blindness Requirements and Protection Rate in the Midterm of Phase III Clinical Trial of COVID-19 Vaccine

摘要: 通过对疫苗保护率的概念延伸，建立了防护措施保护率、防护措施下的疫苗保护率、以及疫苗综合保护率(防护措施和疫苗共同作用下的保护率)等概念。借助新冠疫苗三期试验所在国的防护措施保护率的列表比较，可定性地看出各试验所在国的防护措施保护率对试验进度有着重要的影响，为了加快进度，建议三期试验尽可能选择在防护措施保护率较低的国家进行。分析指出现采用的疫苗保护率在不同的防护措施下的结果缺乏可比性，特别是在防护措施保护率很高的国家，存在疫苗保护率计算的可靠性问题，甚至会出现长时间无法达到现有三期试验中期揭盲人数要求的可能性。我们论述了疫苗综合保护率具有可比性，以及在防护措施保护率较高的情况下，该保护率的相对误差对防护措施下的疫苗保护率的相对误差具有抗干扰的能力，因此建议把该保护率作为对疫苗的有效性进行评价的指标。根据建议的评价指标具有的性质，建议把三期试验中期揭盲的条件修改为，以试验期三个月为限，在总发病人数达到统计学要求时可提前结束。我们还建立了一个判断疫苗保护作用的显著性指标，据此可以判断疫苗在某地接种的必要性。

Abstract: By extending the concept of vaccine protection rate, the concepts of protective measures protection rate, vaccine protection rate under the background of protective measures, and the comprehensive protection rate of vaccines (protection rate under the combined action of protective measures and vaccines) were established. According to the list comparison of the protective measures protection rate of the countries where the phase III trial of COVID-19 vaccine was conducted, the protective measures protection rate which was conducted had an important impact on the trial progress. In order to speed up the progress, it is suggested that the phase III trial should be carried out in the countries where the protective measures protection rate is low as far as possible. It is pointed out that the results of vaccine protection rate are not comparable in the context of different protective measures, especially in countries with high protection rate, there is a problem of reliability in the calculation of vaccine protection rate. There will even be failure to meet the uncovering blindness requirements of the midterm of current phase III trial. We demonstrate the comparability of the protection rate under the combined action of protective measures and vaccines, and that the relative error of the protection rate has the ability of anti-interference to the vaccine protection rate under the protective measures. Therefore, we suggest that the protection rate be used as an index to evaluate the effectiveness of the vaccine. According to the nature of the suggested evaluation indexes, we suggest that the uncovering blindness requirements in the midterm of phase III should be modified as follows: the trial period is limited to three months, and it can be ended earlier when the total number of patients meets the statistical requirements. We have also established a measure of whether the vaccine’s protection is significant, by which we can determine the need for vaccination in a particular location.