Table 1:

Description of key model parameters not fitted in the MCMC and their source

Parameter	Description	Source
β	Age-dependent transmission, split into household, school, work and other	Matrices from Prem et al. [11]
γ	Recovery rate, changes with τ, the relative level of transmission from undetected asymptomatics compared to detected symptomatics	Fitted from early age-stratified UK case data to match growth rate and R0
da	Age-dependent probability of displaying symptoms (and hence being detected), changes with α and τ	Fitted from early age-stratified UK case data to capture the age profile of infection.
σa	Age-dependent susceptibility, changes with α and τ	Fitted from early age-stratified UK case data to capture the age profile of infection.
HR	Household quarantine proportion (set equal to $0.8{\varphi }_t^R$)	Can be varied according to scenario
$N_a^R$	Population size of a given age within each region	ONS