Antibody responses to natural influenza A/H1N1/09 disease or following immunization with adjuvanted vaccines, in immunocompetent and immunocompromised children

• Published in: Vaccine 2011-04, Vol.29 (19), p.3548-3557
• Main Authors: Meier, Sara, Bel, Michael, L’Huillier, Arnaud, Crisinel, Pierre-Alex, Combescure, Christophe, Kaiser, Laurent, Grillet, Stéphane, Pósfay-Barbe, Klara, Siegrist, Claire-Anne
• Format: Article
• Language: English
• Subjects: Adjuvants, Immunologic - administration & dosage; Adjuvants, Immunologic - adverse effects; Adolescent; Allergy and Immunology; Anorexia; Antibodies, Viral - blood; Antibody Formation; Antigens; Applied microbiology; Biological and medical sciences; Child; Child, Preschool; Children; Chronic diseases; Family medical history; Female; Fundamental and applied biological sciences. Psychology; hemagglutination; Hemagglutination Inhibition Tests; Humans; Immunity; Immunization; Immunocompromised Host; Infections; Influenza; Influenza A Virus, H1N1 Subtype - immunology; Influenza Vaccines - immunology; Influenza, Human - immunology; Influenza, Human - prevention & control; Male; Microbiology; Miscellaneous; Neutralization Tests; Pain; Pandemics; Pediatrics; Prospective Studies; Squalene - administration & dosage; Studies; vaccination; Vaccines; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies (general aspects); Virology
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/j.vaccine.2011.02.094

Abstract Objectives To compare antibody responses elicited by influenza A/H1N1/09 disease and immunization with adjuvanted vaccines, in immunocompetent or immunocompromised children. Study design Prospective parallel cohort field study enrolling children with confirmed influenza A/H1N1/09 disease or immunized with 1 (immunocompetent) or 2 (immunocompromised) doses of influenza A/H1N1/09 squalene-based AS03- or MF59-adjuvanted vaccines. Antibody geometric mean titers (GMT) were measured by hemagglutination inhibition (HAI) and microneutralization (MN) assays 4–6 weeks after vaccination/disease. Vaccine adverse events were self-recorded in a 7-day diary. Results Antibody titers were as high in 48 immunocompetent children after a single immunization (HAI and MN seroprotection rates: 98%; HAI-GMT: 395, MN-GMT: 370) as in 51 convalescent children (seroprotection rates: 98% (HAI) and 92% (MN); GMT: 350 (HAI) and 212 (MN). Twenty-seven immunocompromised children reached slightly lower seroprotection rates (HAI: 89%, MN: 85%) but similar antibody titers (HAI-GMT: 306, MN-GMT: 225) after 2 immunizations. Adverse events increased with age ( P = 0.01) and were more frequent with Pandemrix® than Focetria® ( P = 0.03). Conclusions Similarly high seroresponses may be expected in immunocompetent children after a single dose of adjuvanted vaccines as responses of convalescent children. Two vaccine doses were sufficient for most immunocompromised children. Trial registration NCT0102293 and NCT01022905.