A randomized clinical trial assessing immunogenicity and safety of a double dose of virosomal-adjuvanted influenza vaccine administered to unprimed children aged 6-35 months.
This study evaluated the immunogenicity of a double dose of the seasonal virosomal-adjuvanted influenza vaccine (Inflexal V, Crucell, The Netherlands) in 65 previously unvaccinated children aged less than 3 years: 43 received double doses (two doses of 0.50 mL 4 weeks apart) and 22 standard doses (two doses of 0.25 mL 4 weeks apart). Both treatments evoked a response that satisfied the EMEA criteria for adequate immunogenicity for all three vaccine strains, but the double dose had a significantly greater effect on all of the studied parameters of humoral and cell-mediated immune response (p<0.05). This result was achieved without any increase in the incidence of local and systemic adverse events. This means that doubling the dose of the virosomal-adjuvanted influenza vaccine (i.e. administering the same dose as that usually given to older children) effectively and safely increases the immune response to inactivated influenza vaccine in unprimed children aged less than 3 years.
Esposito
Susanna
S
Department of Maternal and Pediatric Sciences, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Commenda 9, 20122 Milan, Italy.
Marchisio
Paola
P
Ansaldi
Filippo
F
Bianchini
Sonia
S
Pacei
Michela
M
Baggi
Elena
E
Trabattoni
Daria
D
Icardi
Giancarlo
G
Principi
Nicola
N
D000276:Adjuvants, Immunologic / Q000494:pharmacology; D000914:Antibodies, Viral / Q000097:blood; D002675:Child, Preschool; D005260:Female; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D007111:Immunity, Cellular; D056724:Immunity, Humoral; D007115:Immunization Schedule; D007223:Infant; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology; D007251:Influenza, Human / Q000276:immunology / Q000517:prevention & control*; D008297:Male; D011446:Prospective Studies; D022721:Vaccines, Virosome / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology
D000276:Adjuvants, Immunologic; D000914:Antibodies, Viral; D007252:Influenza Vaccines; D022721:Vaccines, Virosome