Table 3.
Number of chart-confirmed narcolepsy cases with symptom onset during the 180 days post-vaccination observed versus expected in the Vaccine Safety Datalink population for the 2009 pandemic and 2010–2011 influenza season
| Vaccination Period | Vaccine | Age group, years | Number of people vaccinated | Expected Incidence Rate1 | Expected number of cases | Observed number of cases2 |
|---|---|---|---|---|---|---|
| 2009 pandemic | MIV | < 10 | 229,157 | 1.01 / 100,000 | 1.12 | 0 |
| 10 – 19 | 142,342 | 3.84 / 100,000 | 2.64 | 0 | ||
| 20 – 29 | 67,532 | 1.84 / 100,000 | 0.59 | 0 | ||
| subtotal | 439,031 | 4.35 | 0 | |||
| MLAIV | < 10 | 120,710 | 1.01 / 100,000 | 0.59 | 0 | |
| 10 – 19 | 79,936 | 3.84 / 100,000 | 1.48 | 0 | ||
| 20 – 29 | 11,318 | 1.84 / 100,000 | 0.10 | 0 | ||
| subtotal | 211,964 | 2.17 | 0 | |||
| Total | 650,995 | 6.52 | 0 | |||
| 2010–2011 influenza season | TIV | < 10 | 345,390 | 1.01 / 100,000 | 1.68 | 0 |
| 10 – 19 | 250,006 | 3.84 / 100,000 | 4.62 | 2 | ||
| 20 – 29 | 145,586 | 1.84 / 100,000 | 1.27 | 0 | ||
| subtotal | 740,982 | 7.57 | 2 | |||
| LAIV | < 10 | 81,410 | 1.01 / 100,000 | 0.40 | 0 | |
| 10 – 19 | 45,426 | 3.84 / 100,000 | 0.84 | 0 | ||
| 20 – 29 | 2,712 | 1.84 / 100,000 | 0.02 | 0 | ||
| subtotal | 129,548 | 1.26 | 0 | |||
| Total | 870,530 | 8.83 | 2 | |||
Abbreviations: LAIV = live attenuated influenza vaccine; MIV = monovalent inactivated vaccine; MLAIV = monovalent live attenuated influenza vaccine; TIV = trivalent inactivated vaccine.
1
Expected incidence rates are per 100,000 person-years; from Silber, et al.11
2
Chart-confirmed cases of narcolepsy with or without cataplexy and whose symptom onset date occurred during the 180 days following receipt of one of the vaccines listed in the table.