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

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.

• Authors: Sara Meier, Michael Bel, Arnaud L'huillier, Pierre-Alex Crisinel, Christophe Combescure, Laurent Kaiser, Stéphane Grillet, Klara Pósfay-Barbe, Claire-Anne Siegrist, H1N1 Epidemiology Study Group of Geneva
• Journal: Vaccine (Vaccine) Vol. 29 Issue 19 Pg. 3548-57 (Apr 27 2011) ISSN: 1873-2518 [Electronic] Netherlands
• PMID: 21419775 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2011 Elsevier Ltd. All rights reserved.

Chemical References

• Adjuvants, Immunologic
• Antibodies, Viral
• Influenza Vaccines
• focetria
• pandemrix
• Squalene

Topics

• Adjuvants, Immunologic (administration & dosage, adverse effects)
• Adolescent
• Antibodies, Viral (blood)
• Antibody Formation
• Child
• Child, Preschool
• Female
• Hemagglutination Inhibition Tests
• Humans
• Immunization
• Immunocompromised Host
• Influenza A Virus, H1N1 Subtype (immunology)
• Influenza Vaccines (immunology)
• Influenza, Human (immunology, prevention & control)
• Male
• Neutralization Tests
• Prospective Studies
• Squalene (administration & dosage)