Safety, efficacy, and effectiveness of cold-adapted influenza vaccine-trivalent against community-acquired, culture-confirmed influenza in young children attending day care.
OBJECTIVE
The goal was to evaluate the safety, tolerability, and efficacy of an investigational, refrigerator-stable formulation of live attenuated influenza vaccine (cold-adapted influenza vaccine-trivalent) against culture-confirmed influenza, acute otitis media, and effectiveness outcomes in young children in day care over 2 consecutive influenza seasons.


METHODS
Children 6 to <36 months of age who were attending day care were assigned randomly in year 1 to receive 2 doses of vaccine or placebo intranasally, 35 +/- 7 days apart. In year 2, subjects received 1 dose of the same treatment as in year 1.


RESULTS
A total of 1616 subjects (vaccine: 951 subjects; placebo: 665 subjects) in year 1 and 1090 subjects (vaccine: 640 subjects; placebo: 450 subjects) in year 2 were able to be evaluated for efficacy. The mean age at first vaccination was 23.4 +/- 7.9 months. In year 1, the overall efficacy of the vaccine against influenza subtypes similar to the vaccine was 85.4%; efficacy was 91.8% against A/H1N1 and 72.6% against B. In year 2, the overall efficacy was 88.7%; efficacy was 90.0% against H1N1, 90.3% against A/H3N2, and 81.7% against B. Efficacy against all episodes of acute otitis media associated with culture-confirmed influenza was 90.6% in year 1 and 97.0% in year 2. Runny nose or nasal discharge after dose 1 in year 1 was the only reactogenicity event that was significantly more frequent with cold-adapted influenza vaccine-trivalent (82.3%) than placebo (75.4%).


CONCLUSIONS
Cold-adapted influenza vaccine-trivalent was well tolerated and effective in preventing culture-confirmed influenza illness in children as young as 6 months of age who attended day care.
Vesikari
Timo
T
Tampere University Medical School/FM3, Biokatu 10, 33520 Tampere, Finland. timo.vesikari@uta.fi
Fleming
Douglas M
DM
Aristegui
Javier F
JF
Vertruyen
Andre
A
Ashkenazi
Shai
S
Rappaport
Ruth
R
Skinner
Jonathan
J
Saville
Melanie K
MK
Gruber
William C
WC
Forrest
Bruce D
BD
D000208:Acute Disease; D002656:Child Day Care Centers; D002675:Child, Preschool; D017714:Community-Acquired Infections / Q000517:prevention & control; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology; D053122:Influenza A Virus, H3N2 Subtype / Q000276:immunology; D009981:Influenza B virus / Q000276:immunology; D007252:Influenza Vaccines / Q000627:therapeutic use*; D007251:Influenza, Human / Q000517:prevention & control*; D008297:Male; D010033:Otitis Media / Q000517:prevention & control*; D011446:Prospective Studies
D007252:Influenza Vaccines