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Groups of volunteers were immunized subcutaneously with one of three inacti vated influenza virus A/USSR/77 (HlNl) vaccine preparations; a whole virus vaccine, a surface-antigen subunit adsorbed vaccine, or an aqueous surface-antigen subunit vaccine. The reactions to immunization were recorded, and the antibody response was measured 1 month later. A fourth group of volunteers were inoculated intranasally with live attentuated A/USSR/77 (H1N1) influenza virus; the reactions and antibody response of these volunteers were also measured. One month after immunization, the incidence of infection by challenge with homologous live attentuated virus was determined for all groups of volunteers. The results showed that all four vaccines used were relatively non-reactogenic, and that inactivated vaccines induced higher titres of serum antibody than the live attenuated vaccine. All the vaccines induced significant protection against challenge virus infection which was directly related to the level of serum HI antibody response. [ABSTRACT FROM PUBLISHER]

Specific antibody responses to influenza viral antigens produced by cultured peripheral blood mononuclear leucocytes stimulated with influenza virus or pokeweed mitogen (PWM) have been measured in seven patients with systemic lupus erythematosus (SLE) before and at time intervals alter influenza immunization. Cells from two patients stimulated with influenza virus in vitro produced high levels of specific antibody 7 days after immunization. Cells From a third patient produced small amounts of specific antibody at day 14. No antibody was produced by cells from the remaining four patients. Responses were of short duration and were not detectable I month after immunization. Specific anti-influenza antibody was induced by PWM only from cells of those patients who responded to virus antigen although absolute levels of antibody produced were not as high. In six patients serum haemagglutination inhibiting antibody to influenza virus was measured. and all six had a greater than four-fold increase. The disparity between in vitro antibody production by peripheral blood mononuclear leucocytes and changes in serum antibody suggests that in patients with systemic lupus erythematosus. in vitro functions of peripheral blood lymphocytes do not reflect the immune system as a whole. [ABSTRACT FROM AUTHOR]

In vitro specific antibody responses to influenza viral antigens by peripheral blood mononuclear leucocytes following stimulation with influenza virus or pokeweed milogen have been measured before and at time intervals after influenza immunization in 11 healthy volunteers. There was an early increase in specific antibody produced by lymphocytes stimulated with influenza virus in vitro, in all subjects immunized. The magnitude of the response varied considerably between individuals as did its duration. Virus specific antibody production by cells stimulated with pokeweed mitogen also increased after immunization in all donors. Cells from six of the 11 individuals produced specific antibody in vitro seven days after immunization without antigen or mttogen stimulation Seven of the 11 subjects had a greater than four-fold increase in serum titre of haemagglutination inhibiting antibody. This study shows an early brisk increase in the ability of lymphocytes lo respond to influenza virus in vitro following immunization consistent with a secondary immune response. [ABSTRACT FROM AUTHOR]

The architecture and chemical composition of the influenza virus particle is described with particular reference to the protein constituents and their genetic control. The dominant role in infection of the surface proteins - haemagglutinins and neuraminidases - acting as antigens and undergoing variation in time known as antigenic drift and shift is explained. The immuno-diffusion technique has illuminated the interrelationships of the haemagglutinins of influenza A viruses recovered over long periods of time. The H0 and H1 haemagglutinins are now regarded as a single sub-type with H2 and H3 representing the haemagglutinins of the 1957 and 1968 sub-types. Animal influenza viruses of pigs, horses and birds are described. A relation to human influenza strains has been shown to exist in certain instances as is the capacity of some human strains to pass to the animal kingdom. [ABSTRACT FROM PUBLISHER]

The respective roles of cell-mediated immunity and humoral immunity in host defence were investigated in mice infected with influenza A/PR8 virus. Transferred immune spleen cells were shown to provide full protection only when they were actually secreting antibody. Serum antibody transferred in ‘physiological’ amounts was found to be protective in immunologically intact or in immunosuppressed animals. The specificity of the transferred antibody was shown to be critical, since antibody to internal components of the virus was inefficient while antibody to haemagglutinin, especially that to the strain-specific determinants of the haemagglutinin molecule, was highly efficient. [ABSTRACT FROM PUBLISHER]

Forty-nine subjects were vaccinated with either live attenuated, detergent split, or oil adjuvant A2/Hong Kong influenza vaccines, or a saline influenza B vaccine as control. Respiratory symptoms occurred more frequently in subjects who received the live vaccine but in total there was little difference between the symptoms in the four groups. Antibody titres hi nasal washings and serum were measured by haemagglutination inhibition, neuraminidase inhibition and virus neutralization tests. The oil adjuvant vaccine stimulated larger antibody responses than the other procedures. Six weeks after vaccination the volunteers were challenged with partially attenuated live A2/Hong Kong influenza virus administered intranasally. The live attenuated and oil adjuvant vaccines provided the best protection against challenge. [ABSTRACT FROM PUBLISHER]

Recombination between influenza A viruses as a method of producing strains suitable for use in vaccines is discussed with particular reference to a recombination system involving an attentuated laboratory strain A/PR8/34 (HoN1) and a recent isolate of the epidemic strain A/Hong Kong/68 (H3N2). A variety of properties of the viruses were shown to be segregated independently of one another during recombination. These properties included the envelope antigens (haemagglutinin and neuraminidase), growth capacity in the fertile egg and attenuation for man. Some of the recombinants were considered suitable for use in vaccines either inactivated (whole virus particles or subunits) or live. The application of this technique to future requirements for vaccine strains are discussed with particular reference to the safety aspect of using recombinants in live vaccines. [ABSTRACT FROM PUBLISHER]