Steinherz 1980.

Methods	Single‐centre CCT conducted in New York, USA, during the 1976‐1977 influenza season Responses to influenza vaccine of children with cancer who are receiving chemotherapy were compared with those of healthy siblings and children with cancer off chemotherapy
Participants	160 children, of whom 147 children had various types of malignancies (median age 11.6 years) and 13 siblings served as normal controls (median age 8.6 years). Of the 147 children with cancer, 106 were receiving chemotherapy and 41 had been off chemotherapy for 30 or more days
Interventions	Bivalent split‐product influenza A vaccine intramuscularly, containing the following strains: A/New Jersey/8/76 (Hsw1N1), A/Victoria/3/75 (H3N2). Two doses of 0.5 ml, each containing 200 CCA units, were administered 4 weeks apart
Outcomes	(1) Significant antibody response (defined as four‐fold rise in HI titre) four to six weeks after two immunisations (2) Achieving protective HI antibody titre (defined as ≥ 32) 4 to 6 weeks after two immunisations (3) Adverse reactions after vaccination
Notes	The National Influenza Immunization Program ended in December 1976. By that time, only 50/106 participants receiving chemotherapy and 21/41 participants off chemotherapy had received both immunisations. The age and sex distributions remained similar to those of the original group of 160 participants. Age and sex distributions of the healthy sibling controls are not mentioned

ALL = acute lymphoblastic leukaemia
 CCT = controlled clinical trial
 GMT = geometric mean titre
 HI = haemagglutination inhibition
 RCT = randomised controlled trial