Table 3.

Multivariate Model Selected by a Forward Stepwise Model Building Process

Month 7 variable	OR	95% CI	P value
CD8.Env.poly	0.26	.15–.45	.000
IgG_Env	1.02	.62–1.68	.936
IgG_V2	1.25	.76–2.04	.379
CD8.Env.poly:IgG_Env	1.88	1.11–3.19	.019
CD8.Env.poly:IgG_V2	1.59	1.03–2.47	.037

The candidate variables of vaccinees included pairwise interactions and main effects. At each step the most significant variable was added. If an interaction term was added, all components of the interaction term were added as well. The process stopped when no variable was significant (unadjusted P value < .05) when added to the model. Odds ratio for main effects (rows 1–3) or ratio of odds ratios for interaction terms (rows 4–5), 95% confidence intervals, and P values for all immune response variables in the final model are shown. The analysis adjusts for clinical covariates.

Abbreviations: CI, confidence interval; IgG, immunoglobulin G; OR, odds ratio.