USA_state_N             Population of US states
confirmed               Confirmed COVID-19 cases
death                   Confirmed COVID-19 deaths
eSAIR                   Extended state-space SIR with a subset of the
                        population showing antibody positivity
qh.eSIR                 Extended state-space SIR with quarantine
recovered               Confirmed COVID-19 recovered
tvt.eSIR                Fit extended state-space SIR model with
                        time-varying transmission rates
tvt.eSIR2               Fit extended state-space SIR model with
                        time-varying transmission rates
