Immunity following intranasal administration of an inactivated, freeze-dried A/England/42/72 vaccine.
A group of 23 student volunteers were each inoculated intranasally with 400 IU of inactivated, freeze-dried A/England/42/72 vaccine. Only one volunteer showed a four-fold rise in serum HI antibody following immunization, and the mean increase in serum HI antibody (gmt) for all volunteers did not increase two-fold. Thirteen of the volunteers developed detectable levels of nasal wash neutralizing antibody after immunization; local antibody was most commonly found in volunteers who produced a detectable but less than four-fold fise in serum antibody titre, and who produced nasal washings with relatively high concentrations of protein and secretory IgA. Four weeks after immunization, the vaccinees and a matched group of control subjects were inoculated with attenuated A/England/42/72 (MRC-7) virus. Evidence of infection was found in 14 of 23 (61 per cent) of control subjects and in seven of 23 (30 per cent) of immunized volunteers. This result showed a significant protection (P = 0.04) against challenge virus infection for volunteers given intranasal vaccine.
D000281:Administration, Intranasal; D000328:Adult; D000914:Antibodies, Viral / Q000032:analysis; D000917:Antibody Formation; D005260:Female; D005612:Freeze Drying; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D007109:Immunity; D007070:Immunoglobulin A / Q000032:analysis; D007252:Influenza Vaccines; D007251:Influenza, Human / Q000276:immunology*; D008297:Male; D009297:Nasal Mucosa / Q000276:immunology; D009500:Neutralization Tests; D014613:Vaccines, Attenuated
D000914:Antibodies, Viral; D007070:Immunoglobulin A; D007252:Influenza Vaccines; D014613:Vaccines, Attenuated