Table 4.
Estimates of influenza vaccine effectiveness for adults ≥60 years, REVELAC-i, five South American countries, 2013–2017.
| Cases |
Controls |
aVE † % (95%CI) |
|||
|---|---|---|---|---|---|
| Vaccinated (%) | Unvaccinated (%) | Vaccinated (%) | Unvaccinated (%) | ||
| Any influenza virus | 568 (37) | 956 (63) | 2225 (49) | 2288 (51) | 41 (28, 52) |
| H3N2 | 307 (39) | 484 (61) | 2225 (49) | 2288 (51) | 45 (34, 53) |
| H1N1p | 148 (34) | 283 (66) | 2225 (49) | 2288 (51) | 40 (18, 56) |
| B | 100 (46) | 119 (54) | 2225 (49) | 2288 (51) | 20 (-40, 54) |
| Unvaccinated | Reference | ||||
†
Adjusted for prior vaccination (interaction term), sex, age (in subcategorized age group −60–69, 70–79, 80+ years- for adults 60+), month of illness onset, pre-existing conditions, year and country. Random effect model with a robust variance adjusted for cluster samples (country) by the Huber-White method.