TABLE 1.

Half-lives of PA-X from PR8, pH1N1, Udorn, HK06, and Perth^a

PA-X	Slope of linear regression	Half-life (min)	95% confidence interval on slope
A/Puerto Rico/8/1934	−0.70	86	−0.90 to −0.50
A/California/7/2009pdm pH1N1	−0.29	207	−0.36 to −0.22
A/Udorn/307/1973 H3N2	−1.77	34	−2.41 to −1.14
A/Perth/16/2009 H3N2	−0.39	156	−0.48 to −0.29
A/Hong Kong/218847/2006 H1N1	−0.73	83	−1.07 to −0.38

^aLinear regression was carried out on the quantification plots in Fig. 3, and the slope of the linear regression line and the calculated half-life are reported here. Half-life was calculated as the negative of the inverse of the slope in minutes. The slope and half-life for PR8 PA-X were calculated based on regression analysis from Fig. 1B.