Table 2. Basic reproductive numbers and invasion reproductive numbers before the vaccination program.

Symbol	Description	Value	Reference
	Basic reproductive numbers of vaccine-sensitive strain	6.53	[34], [36]
	Basic reproductive number of vaccine-resistant strain	4.99	[10], [12], [23]
	Invasion reproductive number of vaccine-resistant strain	0.76	–

These values are based on the H7N7 epidemic in The Netherlands in 2003 [32], [33], [34]. The exact expressions of these reproductive numbers are given in Supplementary Information: Text S1.