Table 1.

Nomenclature.

symboldescription
rbirths per year
fmaturity rate
d1juvenile death rate
d2adult death rate
ks,1juvenile death rate from varicella (no vaccine)
ks,2adult death rate from varicella (no vaccine)
kv,1varicella mortality of vaccinated juveniles
kv,2varicella mortality of vaccinated adults
σ1/duration of incubation period
δs1/duration of infectious period (no vaccine)
δv1/duration of infectious period if vaccinated
β1transmission rate—juveniles to juveniles
β2transmission rate—adults to adults, adults to juveniles and juveniles to adults
vvaccination probability
pprobability of primary failure
φprobability of temporary protection
εprobability of becoming infected if vaccinated
bprobability that immunity will be ‘boosted’ if exposed to varicella while vaccine protected
ρrelative infectiousness of breakthrough varicella
ψwaning rate (year−1)
λ1forces of infection in juveniles
λ2forces of infection in adults
pIJinfection probability for juveniles
pBJbreakthrough probability for juveniles
pIAinfection probability for adults
pBAbreakthrough probability for adults
CIJtotal expected costs of infection per case in juveniles
CIAtotal expected costs of infection per case in adults
CBJtotal expected costs of breakthrough infection in juveniles
CBAtotal expected costs of breakthrough infection in adults
Cvvaccination cost
DRdisutility of vaccine refusal (expected cost to individuals who do not receive the vaccine)
DVdisutility of vaccination (expected cost to vaccinated individuals)
Daveaverage disutility to the society (expected societal cost per person)
VNNash equilibrium vaccination coverage