Table 2.
Predictors of Baseline Neutralizing Antibody Responses to H3N2 Vaccine and Circulating Strains in Influenza A Virus (IAV)-Negative and -Positive Patients
| Factor | HK14a | HK14-likeb | Balt17-2a2c | Balt18-3ad | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Df | F Value | P Value | Df | F Value | P Value | Df | F Value | P Value | Df | F Value | P Value | |
| 2017–2018 Asymptomatic, IAV-negative | ||||||||||||
| Age | NA | NA | NA | 26 | 28401 | <.0001* | 26 | 3.7711 | .150 | 26 | 0.687 | .751 |
| Influenza vaccine | NA | NA | NA | 1 | 90570.7 | <.0001* | 1 | 5.5534 | .0997 | 1 | 1.1834 | .356 |
| Sex | 1 | 0.477 | .493 | 1 | 164239.5 | <.0001* | 1 | 12.9095 | .037* | 1 | 0.0197 | .897 |
| Race | NA | NA | NA | 1 | 5379.6 | <.0001* | 1 | 0.04114 | .921 | 1 | 0.3431 | .599 |
| Age × influenza vaccine | NA | NA | NA | 3 | 5316.9 | <.0001* | 3 | 9.1598 | .051* | 3 | 0.3604 | .788 |
| Age × sex | NA | NA | NA | 6 | 97352.4 | <.0001* | 6 | 4.042 | .140 | 6 | 1.0513 | .527 |
| Age × race | NA | NA | NA | 6 | 1214.2 | <.0001* | 6 | 1.31 | .445 | 6 | 0.2569 | .926 |
| Sex × race | NA | NA | NA | 1 | 1935.9 | <.0001* | 1 | 0.1934 | .690 | 1 | 2.147 | .240 |
| Age × sex × vaccine | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| 2017–2018 IAV-positive | ||||||||||||
| Age | 21 | 28.7707 | .009* | 21 | 233.829 | .052* | 21 | 0.9208 | .623 | 21 | 3.2703 | .413 |
| Influenza vaccine | 1 | 25.7262 | .015* | 1 | 125.929 | .054* | 1 | 6.564 | .083 | 1 | 1.0529 | .492 |
| Sex | 1 | 85.0714 | .003* | 1 | 68.481 | .077 | 1 | 0.0041 | .953 | 1 | 0.0068 | .948 |
| Race | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| Age × influenza vaccine | 1 | 4.7832 | .117 | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| Age × sex | 4 | 2.9686 | .199 | 3 | 28.031 | .138 | 3 | 1.1693 | .45 | 3 | 0.7863 | .659 |
| Age × race | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| Sex × race | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
| Age × sex × vaccine | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
Abbreviation: AIC, Akaike information criterion; NA, not applicable.
Best-fit models were developed to analyze the individual and combined effects of age, vaccine status, sex, and race on explaining variability in the neutralizing antibody titer against H3N2 vaccine and circulating viruses in patients without and with confirmed IAV (H3N2) infection. The AIC values are indicated for each virus for models > 2 AIC values less than other models.
aHK14 model AIC value IAV-negative = 828.82; IAV-positive = 422.72.
bHK14-like model AIC value IAV-negative = 166.12; IAV-positive = 195.04.
cBalt17-2a2 model AIC value IAV-negative = 631.44; IAV-positive = 296.72.
dBalt18-3a model AIC value IAV-negative = 533.42; IAV-positive = 249.27.
*Statistically significant effect at P < .05