Distributions of live-attenuated influenza vaccine (LAIV) recipients’ characteristics as a function of lot documentation
| 2013–2014 season | 2014–2015 season | |||||||
| Documented lot (n=47 396) | Missing lot (n=21 101) | Documented lot (n=67 099) | Missing lot (n=19 134) | |||||
| Time of administration | ||||||||
| September | 5% | (2211) | 4% | (848) | 1% | (534) | <1% | (44) |
| October | 46% | (21 947) | 53% | (11 226) | 43% | (29 087) | 40% | (7656) |
| November | 36% | (16 844) | 34% | (7196) | 38% | (25 217) | 41% | (7787) |
| December | 11% | (5211) | 7% | (1557) | 15% | (10 206) | 17% | (3220) |
| January | 2% | (1136) | 1% | (251) | 3% | (1697) | 2% | (331) |
| February | <1% | (38) | <1% | (18) | 1% | (353) | <1% | (83) |
| March | <1% | (9) | <1% | (5) | <1% | (5) | <1% | (13) |
| Age (years) | ||||||||
| 2–4 | 76% | (35 813) | 57% | (12 061) | 69% | (46 070) | 28% | (5371) |
| 5–8 | 10% | (4686) | 17% | (3647) | 13% | (8753) | 39% | (7382) |
| 9–17 | 14% | (6897) | 26% | (5393) | 18% | (12 276) | 33% | (6381) |
| Gender | ||||||||
| Female | 47% | (22 510) | 48% | (10 221) | 48% | (31 934) | 49% | (9351) |
| Male | 53% | (24 886) | 52% | (10 880) | 52% | (35 165) | 51% | (9783) |
| Length of registration at practice | ||||||||
| <1 year | 10% | (4547) | 15% | (3219) | 9% | (5874) | 9% | (1789) |
| ≥1 year | 90% | (42 849) | 85% | (17 882) | 91% | (61 225) | 91% | (17 345) |
| Region | ||||||||
| North | 16% | (7355) | 20% | (4303) | 12% | (8368) | 8% | (1558) |
| England/Midlands | 14% | (6467) | 10% | (2023) | 17% | (11 196) | 11% | (2200) |
| England/South | 29% | (13 913) | 19% | (4022) | 9% | (5868) | 4% | (827) |
| England/London | 13% | (6291) | 13% | (2658) | 5% | (3358) | 1% | (97) |
| Northern Ireland | 7% | (3123) | 5% | (1044) | 15% | (10 239) | 60% | (11 409) |
| Scotland | 11% | (5290) | 27% | (5701) | 11% | (7145) | 3% | (624) |
| Wales | 10% | (4957) | 6% | (1350) | 31% | (20 925) | 13% | (2419) |
| North | 16% | (7355) | 20% | (4303) | 12% | (8368) | 8% | (1558) |
| Number of LAIV recipients by practice | ||||||||
| Lower than per-practice median* | 24% | (11 220) | 19% | (3951) | 25% | (16 804) | 12% | (2354) |
| Per-practice median or higher | 76% | (36 176) | 81% | (17 150) | 75% | (50 295) | 88% | (16 780) |
*The median numbers of LAIV recipients by practice were 107 and 152 in influenza seasons 2013–2014 and 2014–2015, respectively.