Table 4.
Estimated fixed effect of the mixed effect log-linear model on the GMT with time, type of vaccine, a dichotomous variable indicating whether IgG anti-S T0 > 33.8 BAU/ml, and age group as covariates, and an interaction term between time and type of vaccine.
| Healthy adults | Frail elderly | |||||
|---|---|---|---|---|---|---|
| Value | Std.Error | p-value | Value | Std.Error | p-value | |
| Intercept | 8,164 | 0,053 | <0.001 | 6,819 | 0,191 | <0.001 |
| Time T2 vs T1 | -1,247 | 0,048 | <0.001 | -1,436 | 0,156 | <0.001 |
| Comirnaty vs Spikevax | -0,549 | 0,064 | <0.001 | 0,034 | 0,212 | 0,872 |
| Heterologous vs Spikevax | -0,347 | 0,151 | 0,022 | – | – | – |
| Ad26.COV2.S vs Spikevax | -3,317 | 0,173 | <0.001 | -2,600 | 0,385 | <0.001 |
| Vaxzevria vs Spikevax | -2,067 | 0,091 | <0.001 | -0,329 | 0,312 | 0,293 |
| IgG anti-S T0 > 33.8 BAU/ml vs IgG anti-S T0 < 33.8BAU/mL | 1,238 | 0,113 | <0.001 | 2,375 | 0,355 | <0.001 |
| Interaction term: time T2 * Comirnaty | -0,207 | 0,058 | <0.001 | 0,082 | 0,174 | 0,636 |
| Interaction term: time T2 * Heterologous | 0,108 | 0,137 | 0,431 | – | – | – |
| Interaction term: time T2 * Ad26.COV2.S | 0,975 | 0,157 | <0.001 | 1,367 | 0,317 | <0.001 |
| Interaction term: time T2 * Vaxzevria | 0,322 | 0,082 | <0.001 | 0,350 | 0,256 | 0,174 |
*Since Spikevax is the reference, to obtain the relative decrease at T2 (vs T1) we exponentiate the time coefficient and substract 1. To obtain the relative decrease at T2 (vs T1) for the other vaccines, we first exponentiate the sum of the time coefficient and the relative interaction term and then substract 1.