Immunogenicity and Reactogenicity of an Inactivated Quadrivalent Influenza Vaccine Administered Intramuscularly to Children 6 to 35 Months of Age in 2012-2013: A Randomized, Double-Blind, Controlled, Multicenter, Multicountry, Clinical Trial.
BACKGROUND
Influenza attack rates are high in 6- to 35-month-old children; vaccines containing both lineages of influenza B (Yamagata and Victoria), in addition to the H3N2 and H1N1 antigens, may improve protection rates.


METHODS
In a randomized double-blind controlled trial, the immunogenicity and reactogenicity of an inactivated quadrivalent influenza vaccine (QIV) and a trivalent control vaccine (TIV) were assessed.


RESULTS
Six hundred one children (QIV, n = 299; TIV, n = 302) were enrolled at 8 sites in 3 countries. The primary immunogenicity objective was met: the lower limit (LL) of the 2-sided 95% confidence interval (CI) for the seroconversion rate in QIV recipients ranged from 66.6% to 81.3%, which was ≥40% against all 4 strains. The immunogenic superiority of the additional B/Victoria strain in the QIV compared to that in the TIV was confirmed: the LL of the 2-sided 95% CI of the geometric mean titer ratio (QIV/TIV) (6.28 [95% CI, 5.32-7.41]) was greater than 1.5, and the LL of the 2-sided 95% CI for the difference in the seroconversion rate (QIV - TIV) (64.19% [95% CI, 57.65%-69.95%]) was greater than 10%. Injection-site pain and irritability/fussiness were the most commonly reported solicited injection-site and general adverse events, respectively, from days 0 to 6 and were similar in frequency between the groups.


CONCLUSIONS
In children aged 6 to 35 months, a QIV has superior immunogenicity for the added B strain and acceptable immunogenicity for shared strains, with no notable difference in reactogenicity and safety when compared to a TIV.
Canadian Center for Vaccinology, IWK Health Centre and Capital Health, Dalhousie University, Halifax, Nova Scotia, Canada.
Joanne M
JM
Langley
GlaxoSmithKline Vaccines, King of Prussia, Pennsylvania.
Long
L
Wang
Aggarwal and Associates Limited, Brampton, Ontario, Canada.
Naresh
N
Aggarwal
Tecnologia en Investigacion, San Pedro Sula, Honduras.
Agustin
A
Bueso
GlaxoSmithKline Vaccines, King of Prussia, Pennsylvania.
Vijayalakshmi
V
Chandrasekaran
Tecnologia en Investigacion, San Pedro Sula, Honduras.
Luis
L
Cousin
Canadian Center for Vaccinology, IWK Health Centre and Capital Health, Dalhousie University, Halifax, Nova Scotia, Canada.
Scott A
SA
Halperin
GlaxoSmithKline Vaccines, King of Prussia, Pennsylvania.
Ping
P
Li
GlaxoSmithKline Vaccines, King of Prussia, Pennsylvania.
Aixue
A
Liu
Canadian Center for Vaccinology, IWK Health Centre and Capital Health, Dalhousie University, Halifax, Nova Scotia, Canada.
Shelly
S
McNeil
Hospital de Maternidad Nuestra Señora de la Altagracia, Santo Domingo, Dominican Republic.
Lourdes Peña
LP
Mendez
Hospital de Maternidad Nuestra Señora de la Altagracia, Santo Domingo, Dominican Republic.
Luis
L
Rivera
GlaxoSmithKline Vaccines, King of Prussia, Pennsylvania.
Bruce L
BL
Innis
GlaxoSmithKline Vaccines, King of Prussia, Pennsylvania.
Varsha K
VK
Jain
D002170:Canada; D002675:Child, Preschool; D004293:Dominican Republic; D004311:Double-Blind Method; D005260:Female; D006721:Honduras; D006801:Humans; D000071497:Immunogenicity, Vaccine; D007223:Infant; D009981:Influenza B virus / Q000276:immunology; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000009:adverse effects* / Q000276:immunology*; D007251:Influenza, Human / Q000276:immunology / Q000517:prevention & control*; D007273:Injections, Intramuscular; D008297:Male; D015164:Vaccines, Inactivated / Q000008:administration & dosage / Q000009:adverse effects* / Q000276:immunology*
D007252:Influenza Vaccines; D015164:Vaccines, Inactivated
children; immunogenicity; influenza vaccine