| Methods |
Intrapandemic, placebo‐controlled CCT of live attenuated bivalent recombinant vaccine in schoolchildren in the Moscow area during the early part of 1969. Serological surveillance retrospectively showed that A2 Hong Kong caused most of the cases. |
| Participants |
Schoolchildren from 2 boarding schools aged 4 to 7 years and 8 to 15 years. There does not appear to be any attrition. |
| Interventions |
Live attenuated injected vaccine containing A2 and B type antigens, made in the central Moscow laboratories |
| Outcomes |
ILI, pneumonia, bronchitis, OM, tonsillitis, and duration and severity of influenza |
| Funding Source |
Government |
| Notes |
The authors conclude that vaccination did not prevent cases but shortened duration and severity of illness. Unfortunately, no standard deviations are reported for mean duration. The trial is reasonably reported but there is likely selection bias in serological testing. |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Unclear risk |
Pseudo‐random |
| Allocation concealment (selection bias) |
Unclear risk |
Insufficient information |
| Blinding (performance bias and detection bias)
All outcomes |
Low risk |
Double‐blinding |
| Incomplete outcome data (attrition bias)
All outcomes |
Unclear risk |
Number of losses to follow‐up is unknown. |
| Summary assessments |
Unclear risk |
Plausible bias that raises some doubt about the results |
