Example illustration of options to increase influenza vaccination coverage: effectiveness and cost of options comparing with the current situation in four provinces currently without subsidy policy.

ms: months; yrs: years Footnotes: OPTION One denotes measure of a single recall/reminder to parents by phone. OPTION Two denotes comprehensive measures including providing free influenza vaccination voucher to parents during last visit to EPI clinics and expanding influenza vaccination sites in hospitals. MAC denotes medically attended cases including both outpatient and inpatient. Data of season and province specific please see Table S6 in Appendix S1.