An open-label, randomized clinical trial assessing immunogenicity, safety and tolerability of pandemic influenza A/H1N1 MF59-adjuvanted vaccine administered sequentially or simultaneously with seasonal virosomal-adjuvanted influenza vaccine to paediatric kidney transplant recipients.
BACKGROUND
The aim of this study was to investigate the immunogenicity, safety and tolerability of the 2009 A/H1N1 MF59-adjuvanted influenza vaccine, administered sequentially or simultaneously with the seasonal 2009-10 virosomal-adjuvanted influenza vaccine, to paediatric kidney transplant recipients.


METHODS
Thirty-two children and adolescents with transplanted kidneys and 32 age- and gender-matched healthy controls were randomized 1:1 to receive the pandemic vaccine upon enrolment and the seasonal vaccine 1 month later (16 transplant recipients and 16 healthy controls), or to receive the two vaccines simultaneously upon enrolment (16 transplant recipients and 16 healthy controls).


RESULTS
When the pandemic vaccine was administered sequentially to the seasonal vaccine, it was significantly less immunogenic in the patients than in the controls (P < 0.05); when it was administered together with the seasonal vaccine, the immune response of both patients (P < 0.05) and controls (P < 0.05) was significantly greater than when it was administered sequentially. Seroconversion rates and the geometric mean titres of all of the seasonal antigens were significantly lower in the patients, regardless of the type of vaccine administration (P < 0.05). Simultaneous administration was associated with a better immune response against A/H1N1 and A/H3N2 antigens in both patients and controls, and did not increase the mild local and systemic reactions. No impact on renal function was observed.


CONCLUSIONS
Paediatric kidney transplant recipients have a lower immune response to the pandemic influenza A/H1N1 MF59-adjuvanted and seasonal virosomal-adjuvanted influenza vaccines than healthy controls. The simultaneous administration of the two vaccines seems to increase immune response to both pandemic and seasonal A/H1N1 and A/H3N2 antigens, and has the same safety profile as that of the pandemic vaccine administered sequentially to the seasonal vaccine.
Department of Maternal and Pediatric Sciences, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
Susanna
S
Esposito
Elisa
E
Meregalli
Cristina
C
Daleno
Luciana
L
Ghio
Claudia
C
Tagliabue
Antonia
A
Valzano
Domenico
D
Serra
Carlotta
C
Galeone
Alberto
A
Edefonti
Nicola
N
Principi
D000276:Adjuvants, Immunologic / Q000008:administration & dosage; D000293:Adolescent; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000008:administration & dosage*; D007251:Influenza, Human / Q000276:immunology* / Q000517:prevention & control; D007677:Kidney Function Tests; D016030:Kidney Transplantation / Q000276:immunology*; D008297:Male; D020714:Maximum Tolerated Dose; D011136:Polysorbates / Q000008:administration & dosage; D011379:Prognosis; D012307:Risk Factors; D013185:Squalene / Q000008:administration & dosage; D015996:Survival Rate; D022721:Vaccines, Virosome / Q000008:administration & dosage*; D014779:Virus Replication
D000276:Adjuvants, Immunologic; D007252:Influenza Vaccines; C089950:MF59 oil emulsion; D011136:Polysorbates; D022721:Vaccines, Virosome; D013185:Squalene