The immunogenicity and safety of a single 0.5 mL dose of virosomal subunit influenza vaccine administered to unprimed children aged ≥6 to <36 months: data from a randomized, Phase III study.
This study evaluated the immunogenicity, safety and tolerability of a single 0.5 mL dose of the seasonal virosomal subunit influenza vaccine (Inflexal V, Crucell, Switzerland) in 205 healthy, unprimed children aged at least 6 to <36 months, evaluated at four weeks post-vaccination and seven months from baseline. Of the enrolled children, 102 received one single 0.5 mL dose and 103 received the standard two 0.25 mL doses given four weeks apart. Both treatments evoked an immune response that satisfied the EMA/CHMP criteria for yearly vaccine licensing for all three vaccine strains. Exploratory analyses revealed no differences between the groups at four weeks post-vaccination. Furthermore, immunogenicity was maintained seven months after the first vaccination after both the 0.5 mL and standard two 0.25 mL doses. Adverse events were comparable between groups and were as expected according to the safety profile of the vaccine; overall, the vaccine was well tolerated. Our results show that a single 0.5 mL dose effectively and safely provided long-term immunogenicity to all three influenza strains in unprimed children aged at least 6 to <36 months.
Pediatric Clinic 1, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Commenda 9, 20122 Milan, Italy. susanna.esposito@unimi.it
Susanna
S
Esposito
Paola
P
Marchisio
Valentina
V
Montinaro
Sonia
S
Bianchini
Gerrit Jan
GJ
Weverling
Elena
E
Pariani
Antonella
A
Amendola
Valentina
V
Fabiano
Valentina
V
Pivetti
Alessandro
A
Zanetti
Gian Vincenzo
GV
Zuccotti
D000914:Antibodies, Viral / Q000097:blood; D002675:Child, Preschool; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology; D005260:Female; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D007223:Infant; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology*; D007251:Influenza, Human / Q000276:immunology / Q000517:prevention & control*; D008297:Male; D014611:Vaccination / Q000379:methods; D022223:Vaccines, Subunit / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology; D022721:Vaccines, Virosome / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology
D000914:Antibodies, Viral; C475022:Inflexal V; D007252:Influenza Vaccines; D022223:Vaccines, Subunit; D022721:Vaccines, Virosome