Influenza revaccination of elderly travelers: antibody response to single influenza vaccination and revaccination at 12 weeks.
The antibody response to a single influenza vaccination and the effect of influenza revaccination was assessed in healthy elderly persons. Travelers > or =65 years old who had received influenza vaccine before travel were enrolled in the study and were offered a second vaccination after 12 weeks. Geographic and age-matched control subjects received a single vaccination. A second influenza vaccination was not associated with increased adverse effects. There was no significant difference between log(10) hemagglutinin-inhibiting (HI) antibody titers or an HI antibody titer > or =1:40 (considered to be protective) in 28 control subjects and 28 revaccinated travelers for any antigen. Probable protection for influenza A antigens remained high 24 weeks after a single immunization and revaccination (A/Sydney/05/97 [H3N2], 92% and 96%, and A/Beijing/262/95 [H1N1], 80% and 96%, respectively). Response to B/Harbin was less throughout the study. A/Sydney antibody titer was lower with more times vaccinated in the previous 5 years. Therefore, a second vaccine did not enhance the immune response.
Buxton
J A
JA
British Columbia Centre for Disease Control, University of British Columbia, Vancouver, Canada. jane_buxton@vrhb.bc.ca
Skowronski
D M
DM
Ng
H
H
Marion
S A
SA
Li
Y
Y
King
A
A
Hockin
J
J
D000368:Aged; D000369:Aged, 80 and over; D001955:British Columbia; D016022:Case-Control Studies; D005260:Female; D006389:Hemagglutinins, Viral / Q000096:biosynthesis / Q000276:immunology*; D006801:Humans; D007115:Immunization Schedule; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000276:immunology; D007251:Influenza, Human / Q000209:etiology* / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D008297:Male; D009975:Orthomyxoviridae / Q000276:immunology*; D013997:Time Factors; D014195:Travel
D006389:Hemagglutinins, Viral; D007252:Influenza Vaccines