Influenza vaccine, Asian strain; reactions following its use in adults.
A study of reactions following influenza vaccine inoculation of 327 employees of Peralta Hospital, 55 men and 272 women, showed a very low value for significant or severe reactions. The reaction rate as observed with the present monovalent vaccine containing 200 CCA units of Asian strain, Type A influenza virus, was considerably lower than that reported with previous polyvalent vaccines containing up to 1,400 or 1,500 CCA units of total virus content. The absenteeism rate was 1.1 per cent for women, nil for men. The incidence of reactions was much greater in women than in men. Local reactions such as pain, swelling, or redness at the site of injection occurred in 29.1 per cent of men and 35.7 per cent of women. The incidence of systemic reactions-fever, aching, chilliness, headache, nausea and vomiting-was 3.6 per cent in men and 8.8 per cent in women. About 9 per cent of men and 30 per cent of women had both local and systemic reaction. Some 58 per cent of men and 25 per cent of women had no reaction. The greater majority of reactions appeared within five hours after inoculation with influenza vaccine. In adults the prevention of anaphylactic reactions due to the small amount of egg protein in influenza vaccine, can be accomplished by screening for history of hypersensitivity to egg, chicken or chicken feather. In questionable cases, intradermal testing can be done. The reaction rate observed in this study for the present influenza vaccine was so low that it ought not deter immunization.