Previous estimates of the epidemiological parameters of seasonal influenza epidemics found a SI = 2-4 days [28] [29] [30] , and a R t a little over 1 with slight variation between climates; R t = 1.03 in Brazil [31] versus R t = 1.1-1.3 in more temperate climates [32] . A number of studies have retrospectively estimated the transmissibility of influenza pandemics. During the 1918 Spanish influenza A(H1N1) pandemic, when assuming a SI = 4 days, R 0 estimates range from 2.0-4.3 in community settings [33, 34] , and even higher values (R 0 = 2.6-10.6) in confined settings such as ships and prisons [34] . A separate analysis predicted a slightly lower SI of 3.3 in community settings and a SI of 3.81 in confined settings during the 1918 pandemic, and subsequently estimated R 0 values of 1.34-3.21 and 4.97 in these respective settings [35] . R 0 estimates from the 1957 Asian influenza A(H2N2) pandemic range from 1.65-1.68 [36, 37] . During the first wave of the 1968-1969 Hong Kong influenza A(H3N2) pandemic, estimates of R 0 range from 1.06-2.06 and increased to 1.21-3.58 during the second wave [38] .