Table 2.

Example of estimated parameter variations in three HA strain subtypes.

HA strain subtype	Estimated parameters
	θ 1	θ 2	θ 3	θ 4	θ 5
A/Indonesia/5/2005	−10.33	10.27	23913	1240	0.1
A/Japan/305/1957	−11.72	14.4	17379	379.7	0.1
A/Viet Nam/1203/2004	−3.511	26.25	37854	2230	0.2734
SEM of estimated parameters	2.54	4.79	6038.17	534.57	0.058

SEM = standard error of the mean.