title: Immunogenicity and safety of intradermal influenza vaccine in children.
abstract: In order to compare the immunogenicity and safety of different doses of trivalent influenza vaccine (TIV) administered intradermallly (ID) with those evoked by a full dose of intramuscular (IM) virosomal-adjuvanted influenza vaccine (VA-TIV), 112 previously primed healthy children aged ≥ 3 years were randomised to receive 9 μg or 15 μg of each strain of ID-TIV, or a full IM dose (15 μg of each strain) of VA-TIV. The A/H1N1 and A/H3N2 seroconversion and seroprotection rates were ≥ 90% and geometric mean titres (GMTs) increased 3.2-14.9 times without any statistically significant between-group differences; however, the seroconversion and seroprotection rates against the B strain were significantly higher in the children receiving either ID-TIV dose (p<0.05) without any differences between them. GMT against B virus was significantly higher in the children receiving the highest dose (p<0.05). Local reactions were significantly more common among the children receiving either ID-TIV dose (p<0.05), but systemic reactions were relatively uncommon in all three groups. Our findings suggest that ID-TIV with 15 μg of each viral antigen can confer a significant better protection against influenza than that obtained with the same dose of IM TIV in already primed children aged ≥ 3 years with an acceptable safety profile. The lower dose of ID-TIV needs further evaluation to analyze persistence of protection.
authors.affiliation: Department of Maternal and Pediatric Sciences, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Commenda 9, 20122 Milan, Italy.
authors.forename: Susanna
authors.initials: S
authors.lastname: Esposito
authors.forename: Cristina
authors.initials: C
authors.lastname: Daleno
authors.forename: Irene
authors.initials: I
authors.lastname: Picciolli
authors.forename: Laura
authors.initials: L
authors.lastname: Tagliaferri
authors.forename: Alessia
authors.initials: A
authors.lastname: Scala
authors.forename: Giulia
authors.initials: G
authors.lastname: Prunotto
authors.forename: Valentina
authors.initials: V
authors.lastname: Montinaro
authors.forename: Carlotta
authors.initials: C
authors.lastname: Galeone
authors.forename: Nicola
authors.initials: N
authors.lastname: Principi
mesh_terms: D000914:Antibodies, Viral / Q000097:blood; D002648:Child; D002675:Child, Preschool; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology; D005260:Female; D006801:Humans; 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 / Q000008:administration & dosage / Q000009:adverse effects* / Q000276:immunology*; D007251:Influenza, Human / Q000517:prevention & control*; D007271:Injections, Intradermal; D007273:Injections, Intramuscular; D008297:Male; D014611:Vaccination / Q000379:methods*
chemical_list: D000914:Antibodies, Viral; D007252:Influenza Vaccines