The transmission coefficient is needed for models of Transmission where for instance a vector carries a pathogen or parasite between hosts.
It is represented by β and it is the rate at which a pathogen moves from infected individuals to susceptible individuals in the population.
[1][2] The transmission coefficient is used in the equation: :
− γ
{\displaystyle {\frac {dY}{dt}}={\frac {\beta XY}{N}}-\gamma Y}