Mitigation and herd immunity strategy for COVID-19 is likely to fail

Wolfgang Bock; Barbara Adamik; Marek Bawiec; Viktor Bezborodov; Marcin Bodych; Jan Pablo Burgard; Thomas Goetz; Tyll Krueger; Agata Migalska; Barbara Pabjan; Tomasz Ozanski; Ewaryst Rafajlowicz; Wojciech Rafajlowicz,; Ewa Skubalska-Rafajlowicz; Sara Ryfczynska; Ewa Szczurek; Piotr Szymanski

Here, successful means that even at the peak of the outbreak the epidemic stays below the capacity threshold of intensive care units. Our capacity thresholds for Germany and Poland are based on public statistical sources 14, 15 and on the very moderate assumption that only 80% of the existing ICU places are occupied 16 . The upper bound for R* of those intervals is denoted by R max . This value is transferred into an average per day growth rate of prevalence, as it is reported by most health offices in their daily situation reports. An average per day growth rate was calculated from the first 50 days of the epidemic. We defined R max as the smallest R* value for which 10 sample paths surpassed the ICU threshold within D days. For cities D was chosen to be 200 days and for countries 700 days. The critical value R min was defined as the largest R * < R max for which the daily incidence at day 200 was below 50% of the initial number N o of infected (N o = 100 for Wroc law, N o = 1000 for Berlin, N o = 1000 for Poland and N o = 15000 for Germany). As can be seen from the values in Table 2 , all intervals for a successful mitigation are small, which is below 0.11 in units of R * .