Table 4.
Adjusted Relative VE and Corresponding 95% CIs for Symptomatic COVID-19, Stratified by Age Group and by Age Group and History of Prior SARS-CoV-2 Infection
| Age, y | Overall | No Prior Infection | Prior Infection >3 mo Ago |
|---|---|---|---|
| VE (95% CI) | VE (95% CI) | VE (95% CI) | |
| 5–11a | 63.64 (45.42–75.79) | 58.89 (33.87–74.45)b | 75.74 (64.98–83.20)b |
| 12–17 | 52.82 (40.58–62.53) | 50.35 (36.14–61.40) | 59.64 (40.84–72.46) |
| 18–49 | 47.08 (43.52–50.41) | 46.94 (42.18–51.35) | 47.31 (45.59–49.90) |
| 50–64 | 37.91 (34.77–40.90) | 37.54 (33.56–41.28) | 39.06 (38.90–42.07) |
| ≥65 | 31.44 (27.74–34.95) | 30.81 (27.10–34.32) | 34.64 (17.81–48.01) |
Relative vaccine effectiveness compares those who received 2–4 original wild-type doses plus a BNT162b2 BA.4/5 bivalent vaccine ≥14 days before testing for SARS-CoV-2 and those who received 2–4 original wild-type mRNA doses >2 months ago but not a BA.4/5 bivalent vaccine.
Models clustered on US Census region of pharmacy and adjusted for age (continuous), gender, race/ethnicity, recent contact with someone with confirmed or presumed to have COVID-19, prior SARS-CoV-2 infection, time since last wild-type dose, calendar week of SARS-CoV-2 test (categorical; 2-week intervals), US Census region of pharmacy, area deprivation index for pharmacy location (continuous), store-specific percent positivity in the week prior to the SARS-CoV-2 testing date, and local county-level case incidence per 100 000 persons during the week prior to the SARS-CoV-2 testing date.
Abbreviations: CI, confidence interval; COVID-19, coronavirus disease 2019; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; VE, vaccine effectiveness.
aTwo individuals with gender Other removed from the stratified estimates due to zero cell counts and failure of model to run as a result.
bOn the multiplicative scale, effect modification by prior infection was statistically significant for the 5–11-year-old age group.