IFNA1 and infection: The above reasoning in conjunction with the parsimony principle and numerous trials to fit the in vivo data with different selections of adjusted parameters led us to conclude that a minimal set of three parameters ensured a consistent fitting of the vivo infection data: the infection rate  (reduced by 60-fold), the 50% inhibition threshold  (increased by 10-fold) and the IFN secretion rate  (reduced by 3 fold) for Mφs (Table 1).