Hemagglutination inhibiting antibodies and protection against seasonal and pandemic influenza infection - 17/01/15
Summary |
Objectives |
Hemagglutination inhibiting (HI) antibodies correlate with influenza vaccine protection but their association with protection induced by natural infection has received less attention and was studied here.
Methods |
940 people from 270 unvaccinated households participated in active ILI surveillance spanning 3 influenza seasons. At least 494 provided paired blood samples spanning each season. Influenza infection was confirmed by RT-PCR on nose/throat swabs or serum HI assay conversion.
Results |
Pre-season homologous HI titer was associated with a significantly reduced risk of infection for H3N2 (OR 0.61, 95%CI 0.44–0.84) and B (0.65, 95%CI 0.54–0.80) strains, but not H1N1 strains, whether re-circulated (OR 0.90, 95%CI 0.71–1.15), new seasonal (OR 0.86, 95%CI 0.54–1.36) or pandemic H1N1-2009 (OR 0.77, 95%CI 0.40–1.49). The risk of seasonal and pandemic H1N1 decreased with increasing age (both p < 0.0001), and the risk of pandemic H1N1 decreased with prior seasonal H1N1 (OR 0.23, 95%CI 0.08–0.62) without inducing measurable A/California/04/2009-like titers.
Conclusions |
While H1N1 immunity was apparent with increasing age and prior infection, the effect of pre-season HI titer was at best small, and weak for H1N1 compared to H3N2 and B. Antibodies targeting non-HI epitopes may have been more important mediators of infection-neutralizing immunity for H1N1 compared to other subtypes in this setting.
Le texte complet de cet article est disponible en PDF.Highlights |
• | The determinants of influenza immunity were examined in an unvaccinated cohort. |
• | The risk of H3N2 and B infection decreased with increasing pre-season HI titer. |
• | Pre-season HI titer had less effect on H1N1 infection. |
• | H1N1 immunity increased with age and seasonal H1N1 induced pandemic H1N1 immunity. |
• | The contribution of non-HI antibodies to immunity may be relatively high for H1N1. |
Keywords : Influenza, Human, Hemagglutination inhibition tests, Immunity, Humoral, Antibody, Neutralizing, Pandemics, Humans
Plan
Vol 70 - N° 2
P. 187-196 - février 2015 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
L’accès au texte intégral de cet article nécessite un abonnement.
Déjà abonné à cette revue ?