Figure 2.

Geometric mean (GMT) hemagglutination inhibition (HAI) and neuraminidase inhibition (NAI) titers at prevaccination, and 1, 6, 12, and 18 month postvaccination time points, by intervention, with estimated regression lines*. *Rates of antibody change were estimated in linear mixed models with log₂ titers as the dependent variable and time in days from the 1 month postvaccination blood draw as the independent variable. To account for correlation of titers within individuals over time, the intercept and time were modeled as random effects. Abbreviations: IIV, inactivated influenza vaccine; LAIV, live attenuated influenza vaccine.