RT Journal Article SR Electronic T1 Long-term study of influenza in families JF The Journal of the Royal College of General Practitioners JO J R Coll Gen Pract FD British Journal of General Practice SP 351 OP 356 VO 31 IS 227 A1 The Royal College of General Practitioners and The Public Health Laboratory Service YR 1981 UL http://bjgp.org/content/31/227/351.abstract AB This is an account of a five-year study of influenza in families during an interepidemic period. Proven influenza seemed to be a more severe illness than an influenza-like illness. The result of the study suggests that factors other than strain-specific antibodies may be responsible in protecting against influenza during a period of drift.