get_WHO_region          Look up a country's WHO region
get_country_cocirculation_data
                        Get data on the relative circulation of each
                        influenza A subtype
get_country_inputs_1997_to_present
                        Return raw flu surveillance data for a specific
                        country
get_country_intensity_data
                        Get the relative intensity of influenza A
                        circulation
get_imprinting_probabilities
                        Calculate imprinting probabilities
get_p_infection_year    Calculate the probability imprinting occurs n
                        years after birth
get_regional_inputs_1997_to_present
                        Return raw flu surveillance data for a specific
                        WHO region
get_template_data       Get country-independent flu circulation data
                        for 1918-1996
plot_many_country_years
                        Plot imprinting probabilities for up to five
                        country-years
plot_one_country_year   Plot imprinting probabilities for a single
                        country and year
show_available_countries
                        Show a list of all available countries
show_available_regions
                        Show all WHO regions
