aa Powers 1995a.
| Methods | Randomised controlled trial conducted in the USA during the 1993 to 1994 influenza season. Follow‐up was not indicated. Influenza period was not defined. Participants were randomly assigned to receive 1 of the following 5 vaccine preparations in a double‐blinded manner: 15 mg of rHA0, 15 mg of rHA0 plus alum, 90 mg of rHA0, licensed, and placebo. Spring sera were collected. | |
| Participants | 34 healthy university students: 26 treated and 8 placebo. Age of participants was 18 to 45. | |
| Interventions | Subvirion licensed trivalent parenteral AB vaccine. Schedule and dose were: single dose; 15 µg each strain. Vaccine composition was: A/Texas/36/91 (H1N1), A/Beijing/32/92 (H3N2), and B/Panama/45/90. Placebo was saline for injection. Vaccine was recommended and matched circulating strain. | |
| Outcomes | Clinical and laboratory‐confirmed cases and adverse effects. An "influenza‐like illness" was defined as the presence of any respiratory symptom(s) for >= 2 days, accompanied by fever or systemic symptoms of myalgia or chills. Laboratory evidence of influenza A (H3N2) virus infection was defined as either or both of the isolation of virus from nasopharyngeal secretion and a >= 4‐fold increase in serum HI antibody titre between the 3‐week postvaccination (preseason) specimen and the corresponding postseason specimen collected in the following spring. Local adverse effects were erythema, pain, tenderness, induration, arm stiffness; systemic adverse effects: were headache, generalised myalgia, diarrhoea, nausea, feverishness, temperature > 37.8 °C. | |
| Notes | Efficacy and safety data were extracted. Government funded |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Insufficient information to judge |
| Allocation concealment (selection bias) | Unclear risk | Insufficient information to judge |
| Blinding (performance bias and detection bias) All outcomes | Unclear risk | Insufficient information to judge |
| Incomplete outcome data (attrition bias) All outcomes | Unclear risk | Insufficient information to judge |
| Summary assessment | Unclear risk | Unclear |