ab Goodeve 1983.

Methods	Randomised controlled trial, double‐blind
Participants	119 healthy young adults from the Medical and Science Faculties of Sheffield University, UK, aged 18 to 19 years without egg allergy
Interventions	Purified subunit monovalent B/Hong Kong/73 flu vaccine prepared in 4 antigen concentrations of 40, 20, 10, 5 µg of HA per each 0.5 mL dose versus saline placebo (0.5 mL dose) subcutaneously administered. Participants were divided into 5 groups of equal dimensions (no further description), each group received 1 of the tested coded preparations. Artificial challenge 1 month later with live attenuated RB77 virus.
Outcomes	Local and systemic reactions were assessed by means of questionnaires completed by participants 24 hours after immunisation. Local reactions (including redness, swelling, itching), local pain (including pain on pressure, pain on contact, continuous pain).
Notes	Safety data only were extracted. Government funded
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Unclear
Allocation concealment (selection bias)	Unclear risk	Unclear
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Unclear
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Unclear
Summary assessment	Unclear risk	Unclear