Abstract

The phase Ⅲ vaccine trial is a field evaluation. It is of important value to study the current evaluation indicators of vaccine protection effect and the existing eligibility criteria for testing vaccines that are affected by local public health measures. We derive the magnification between the statistical bias of the incidence in phase Ⅲ vaccine trials and the bias of the current vaccine protection rate. This magnification is directly controlled by the public health protection rate, the greater the public health protection rate, the greater the magnification times. It reveals the internal mechanism that the current vaccine protection rate is not suitable for the evaluation of vaccines. The correctness of the conclusions was further verified using data from the phase Ⅲ trial of the available COVID-19 vaccine.

An equivalent relationship with the existing eligibility criteria for testing vaccines was established by using the comprehensive protection rate with comparability and computational stability. It is proved that with the increase of public health protection rate, the existing eligibility criteria for testing vaccines will lead to the difficulty of vaccine approval.

Keywords: Vaccine; Phase Ⅲ clinical trials; Public health measures; Comprehensive protection rate; Vaccine protection rate.