Table 4 Parameter values for the relative risk of infection, β.

β^v

Mask-off (i.e. not wearing a mask) and both the infected and susceptible individuals are not vaccinated.

1

No change in probability of infection.

Mask-off and infected individual i is vaccinated.

0.5

Mean probability of transmitting infection reduces by 50%²⁷.

Mask-off and susceptible individual j is vaccinated.

0.5

Mean probability of acquiring infection reduces by 50%^13,25,26.

Mask-off and both infected individual i and susceptible individual j are vaccinated.

0.25

Mean probability of infection reduces by 75%. Assumes the effect of vaccination on transmission and acquiring infection is independent.

β^mv

Mask-on (i.e. wearing a mask) only.

0.2

Mean probability of infection reduces by about 80% when both the infected individual and susceptible contact are wearing a mask²⁸.

Mask-on and infected individual i is vaccinated.

0.1

Mean probability of infection reduces by about 90%. Assumes the effect of vaccination and mask wearing on reducing the probability of transmitting infection is independent.

Mask-on and susceptible individual j is vaccinated.

0.1

Mean probability of infection reduces by 90%. Assumes the effect of vaccination and mask wearing on reducing the probability of acquiring infection is independent.

Mask-on and both infected individual i and susceptible individual j are vaccinated.

0.05

Mean probability of infection reduces by 95%. Assumes the effect of vaccination and mask wearing on reducing the probability of transmission and acquiring infection is independent.