PURPOSE OF THE STUDY.
To create an “antibody landscape” for influenza virus to better understand our immunity to this pathogen over time and create more effective influenza vaccines.
A subset of 69 individuals from the Ha Nam Household cohort study in Vietnam were selected based on provisional serological data. This subset of participants included 36 individuals from 6 households with high sampling compliancy, 10 individuals with polymerase chain reaction–confirmed infection, 14 with serological conversion, and 9 controls. An additional 225 individuals from 2 Australian studies were selected for pre- and postinfluenza vaccination serological analysis. Study participants were ≥5 years in age.
Serum samples from the Ha Nam cohort were obtained annually from 2007 to 2012 and at the onset of each influenza-like illness to follow the evolution of their influenza immune profiles. Serum was collected from the additional 225 individuals pre and 26 to 33 days postvaccination with the influenza vaccine. Antigenic cartography, using specialized software, positioned sera and viruses on a map based on their 1H titrations to 81 influenza virus strains spanning 43 years of influenza virus evolution.
Upon infection and vaccination, influenza 1H titers increased broadly, including titers to previously encountered viruses far beyond the extent of cross-reactivity observed after a primary infection. Using antigenically advanced viruses (those that have only recently emerged) for vaccination had the dual benefit of inducing antibodies against both advanced and previous antigenic clusters.
These results indicate that preemptive vaccine updates may improve influenza vaccine efficacy in previously exposed individuals.
Influenza is notorious for escaping immunity induced by before infection or vaccination by changing the molecular structure recognized by antibodies. Currently, vaccine strain updates are based on the analysis of circulating viruses but do not consider the influence of antibody responses to previous vaccines or infections. The authors have developed a direct visualization method to illustrate complex serological patterns, allowing basic insights into the breadth of antibody responses to influenza or other antigenically variable pathogens. Antibody landscapes will likely be useful for the evaluation of evolutionary selection pressures and could lead to the production of more effective vaccines.
- Copyright © 2015 by the American Academy of Pediatrics