| Methods |
See aa Belshe 1998
|
| Participants |
1358 healthy children who previously participated in year 1 of trial (aa Belshe 1998). Aged 26 to 85 months |
| Interventions |
Revaccination with live attenuated, cold‐adapted trivalent (H1N1, H2N3, and B) influenza vaccine, administered by nasal spray |
| Outcomes |
Primary endpoint of efficacy: first episode of culture‐confirmed influenza occurring in an individual child after revaccination Subtype specific efficacy (A and B) Influenza: any illness detected by active surveillance associated with positive culture for wild‐type influenza virus Strain‐specific antibody responses to vaccine Adverse reactions: increase in temperature, decreased activity, irritability, runny nose or nasal congestion, sore throat, cough, headache, muscle aches, chills, vomiting, OM Serious adverse events occurring at any time during the study Incidences of flu‐like illness detected by surveillance |
| Funding Source |
Government/industry |
| Notes |
|
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Unclear risk |
Second year of study of aa Belshe 1998 not re‐randomised |
| Allocation concealment (selection bias) |
Unclear risk |
Second year of study of aa Belshe 1998, not sufficient description |
| Blinding (performance bias and detection bias)
All outcomes |
Low risk |
Double‐blinding |
| Incomplete outcome data (attrition bias)
All outcomes |
Unclear risk |
At the start of the second study year (aa Belshe 1998) only 86% in the treatment arm and 83% in the placebo arm, from the first study year (aa Belshe 1998) were enrolled but insufficient information given to the end of this second study year |
| Summary assessments |
High risk |
Plausible bias that raises some doubt about the results |
