ANTIGENIC RESPONSE TO INFLUENZA VIRUS IN MAN .2. NEUTRALIZING ANTIBODY RESPONSE TO INACTIVATED MONOVALENT B VACCINE, WITH OBSERVATIONS ON VACCINE EFFICACY DURING A SUBSEQUENT TYPE B EPIDEMIC

Brown, P., D. C. Gajdusek, K. M. Chen and J. A. Morris (NIH, Bethesda, Md. 20014). Antigenie response to influenza virus in man. II. Neutralizing antibody response to inactivated monovalent B vaccine, with observations on vaccine efficacy during a subsequent type B epidemic. Amer. J. Epid. 1969, 90: 336-343.-Immunization with one of two inactivated monovalent influenza virus type B vaccines, containing either the Great Lakes/1739/54 or Maryland/1/59 strains, was carried out in the populations of several isolated Pacific Islands for whom historical information and serologic testing had yielded a precise knowledge of earlier exposure, or lack of exposure, to influenza type B. Eighty per cent of people without prior exposure to influenza failed to respond with neutralizing antibody after a single dose of vacdne; the remainder responded at very low levels. A booster injection, given 7 months after the initial dose, uniformly produced a 4-fold or greater rise in homologous antibody, with comparable but usually somewhat lesser rises to all tested heterologous strains, except the distantly related Lee/-/40 strain, to which little or no response occurred. In people who had had a single natural infection 15 years before with influenza type B, the greatest response occurred following the first dose of vacdne, with little or no rise after the booster.Five months after the booster vaccination an epidemic of influenza type B occurred in one of the island populations studied. Neither the incidence of infection nor disease was reduced in the segment of the population given type B vaccine when compared with a control group given type A vaccine. However, a modest reduction in the severity of acute disease in the Great Lakes vaccine group was apparent in a lower incidence of fever, pharyngitis, and gastro-intestinal symptoms, and within a native high school community, of complicating otitis media. © 1969, by THE JOHNS HOPKINS UNIVERSITY.