A live attenuated H9N2 influenza vaccine is well tolerated and immunogenic in healthy adults.
Development of live attenuated influenza vaccines (LAIV) against avian strains with pandemic potential is an important public-health strategy. Either 1 or 2 10(7)-TCID(50) doses of H9N2 LAIV A/chicken/Hong Kong/G9/97 were administered intranasally to 50 adults in isolation; 41 participants were H9N2 seronegative, 24 of whom received 2 doses. The vaccine was well tolerated; vaccine shedding was minimal. After 2 doses, 92% of H9-seronegative participants had > or = 4-fold increases in hemagglutination-inhibition antibody, and 79% had > or = 4-fold increases in neutralizing antibody; 100% had responses detected by at least 1 assay. Although replication of the H9N2 LAIV was restricted, 2 doses were immunogenic in H9N2-seronegative adults. Trial registration. ClinicalTrials.gov identifier: NCT00110279 .
Karron
Ruth A
RA
Center for Immunization Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA. rkarron@jhsph.edu
Callahan
Karen
K
Luke
Catherine
C
Thumar
Bhagvanji
B
McAuliffe
Josephine
J
Schappell
Elizabeth
E
Joseph
Tomy
T
Coelingh
Kathleen
K
Jin
Hong
H
Kemble
George
G
Murphy
Brian R
BR
Subbarao
Kanta
K
D000328:Adult; D000914:Antibodies, Viral / Q000097:blood; D004334:Drug Administration Schedule; D006801:Humans; D053127:Influenza A Virus, H9N2 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000009:adverse effects* / Q000276:immunology*; D007251:Influenza, Human / Q000276:immunology*; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology
D000914:Antibodies, Viral; D007252:Influenza Vaccines; D014613:Vaccines, Attenuated