R_0 or R_eff? admittedly this is a question best directed to an epidemiologist, for which I am not. Science has known for decades that nonpharmaceutical interventions for respiratory pandemics induces artificial heard immunity by reducing the rate of transmission. That rate is the easiest part of the rate of growth (or decay) for us to manipulate.
basic information on the math behind R numbers.
R_0 = transmission rate/recovery (clearance rate). When R_0 (or R_eff) < 1 infectious diseases will die out. The reason for this is due to exponential growth/decay.
:
Given that C_i=C_0*e^(rt) where;
C_i is case incidence rate at time t;
C_0 is initial number of cases;
r = growth/decay rate = transmission rate - recovery/removal rate