Table 4.
Effectiveness of influenza vaccination in oncohematological children.
| Oncohematological patients vaccinated against influenza (n = 91) |
||||
|---|---|---|---|---|
| Off therapy <6 months (n = 46) | Effectiveness of vaccination (%) | Off therapy 6–24 months (n = 45) | Effectiveness of vaccination (%) | |
| N with at least one URTI (%) | 21 (45.7) | 50.0a | 18 (40.0) | 25.0 |
| Mean n of URTIs ± SD | 0.52 ± 0.79 | 81.0b | 0.46 ± 0.73 | 33.3 |
| N with at least one LRTI (%) | 5 (10.9) | 66.6b | 4 (8.9) | 20.7 |
| Mean n of LRTIs ± SD | 0.15 ± 0.28 | 77.6a | 0.08 ± 0.16 | 52.9 |
| N with at least one infection other than ILI (%) | 20 (43.4) | 16.9 | 7 (15.5) | 22.5 |
| Mean n of infections other than ILI ± SD | 0.67 ± 0.88 | 20.2 | 0.22 ± 0.64 | 16.0 |
| N with at least one hospitalisation (%) | 5 (10.9) | 86.1 | 3 (6.7) | 74.9 |
| Mean n of days with fever ± SD | 1.63 ± 1.91 | 65.6b | 1.40 ± 1.63 | 15.7 |
| Mean n of antibiotic courses ± SD | 0.45 ± 1.01 | 87.3b | 0.44 ± 0.96 | 56.9 |
| Mean n of days lost from school ± SD | 1.36 ± 1.90 | 85.6b | 1.33 ± 1.49 | 56.8 |
URTI, upper respiratory tract infection; LRTI, lower respiratory tract infection; ILI, influenza-like illness; SD, standard deviation; ap < 0.05 and bp < 0.0001 vs oncohematological patients off therapy for 6–24 monts. Vaccine effectiveness = 1 minus attack rate (defined as the event rate divided by the total population) among vaccinated oncohematological children divided by the attack rate among unvaccinated oncohematological children [16]. This table represented numbers observed in oncohematologic patients vaccinated against influenza off therapy for <6 months or off therapy for 6–24 months, and vaccine effectiveness was calculated comparing these numbers with those reported in Table 2 regarding oncohematological patients not vaccinated against influenza.