Clinical Trials of Oil-adjuvant Influenza Vaccines, 1960–3

Abstract

Influenza vaccine prepared by emulsifying an aqueous suspension of inactivated virus in mineral oil is a far more potent antigen than the aqueous suspension alone. This fact was confirmed by the Committee in serological trials carried out in 1953 (M.R.C., 1955), but subsequent large-scale clinical trials in 1954-5 failed to show any protective effect, almost certainly because there was very little influenza during that winter (M.R.C., 1957). Unfortunately a small proportion (3.0 per thousand) of the volunteers who received oil-adjuvant vaccine developed persistent local reactions, similar to those described in the United States by Philip et al. (1954). These reactions were usually first noticed as fibrotic nodules several months after inoculation and took a year or more to resolve. In about half the cases (1.8 per thousand) the nodules became large and fluctuant and cleared only after incision.