Common use of Sample Size Considerations Clause in Contracts

Sample Size Considerations. Sample size calculations based on various incidence rates in the control arm, relative vaccine efficacies for those in the MVA-NP+M1 arm, and alpha levels (two-sided) are provided in Table 7-1. All calculations assume 80% power and given this is a proof of concept study an alpha of 0.1 is chosen for powering analyses. Based on the projected range of incidence rates in the control arm, a total sample size of approximately 5000 to 6000 participants over two influenza seasons is expected to provide approximately 80% power to detect a meaningful vaccine efficacy (approximately 35%) in the MVA-NP+M1 arm. After the first influenza season, which will enrol approximately 2,200 participants, a sample size recalculation may be performed on the basis of the observed relative vaccine efficacy of MVI-NP+M1 during the first influenza season. This will be described in more detail in the SAP.