Immune states.

Abstract

<p>The immune states and their transitions for infection and vaccine induced immunity. For individuals in the non-immune categories the time in this category depends on the infection rates and vaccination strategies. For other immune states, time in the state before losing immunity is sampled from a defined distribution, modulated by exposure/vaccination history. Where there are multiple possible transitions out of a state, conditional probabilities determine which path an individual follows. The order in which the probabilities are applied is specified in the text. <i>P₆</i>, <i>P₇</i>, <i>P₈</i> refer to subclinical infections, <i>P₉</i>, <i>P₁₀</i> to clinical infections. <i>P₁₁, P₁₂</i> probabilities of inducing immunity in non-vaccinated individuals, <i>P₁₃, P₁₄, P₁₅</i> in previously vaccinated individuals.</p