COVID-19: Predictions for SARS-CoV-2 vaccination on the course of the pandemic and critical occupancy of intensive-care facilities in Germany.

Braun, Peter; Braun, Julian; Woodcock, Barry G

AIMS OF THE STUDY To obtain predictions using the Modified Bateman SIZ Model for the effects of vaccination on the course of the COVID-19 pandemic in Germany. MATERIALS AND METHODS Start parameters for the model were obtained from observational data after data-smoothing to reduce between-day variation. Three scenarios, 1) no vaccination, 2) vaccination of 60% of the population over 12 months, 3) vaccination of 60% of the population over 7 months were examined. The effects of changes in tα (doubling-time for the spread of infection, known to be slower in the summer months) and tβ (half-life of recovery from infection) on the daily number of infectious persons, the cumulative number of infected persons, and the duration of critical occupancy of intensive-care units were also determined. RESULTS Vaccination produced a marked and rapid reduction in the number of infectious persons (up to -60%) and the total number of infected persons (up to -70%). A 7-month vaccination strategy was significantly more effective than a 12-month strategy. The summer effect came too late to have an additional effect on the spread of infection. Vaccination was predicted to reduce the duration of critical occupancy of intensive-care facilities by ~ 70%. DISCUSSION The predictions are based on the assumptions that lockdown conditions are maintained and vaccine availability is not limiting. CONCLUSION Predictions made using the model show that vaccination with a SARS-CoV-2 vaccine can markedly reduce the spread of the COVID-19 disease and the period of critical occupancy of intensive-care facilities in Germany.