@article{PAR00007540,
  title = {{A}ssociation between pandemic and seasonal influenza vaccination and haemagglutination antibody titers against {A}/{H}1{N}1v : a national representative survey in {F}rance, nested in the "{C}ohorts for {P}andemic {I}nfluenza' ({C}o{P}an{F}lu - {F}rance)},
  author = {{L}apidus, {N}. and de {L}amballerie, {X}avier and {S}alez, {N}. and {M}oyen, {N}. and {F}errari, {P}. and {G}ougeon, {M}. {L}. and {V}ely, {F}. and {L}eruez-{V}ille, {M}. and {A}ndreoletti, {L}. and {C}auchemez, {S}. and {B}oelle, {P}. {Y}. and {V}ivier, {E}. and {A}bel, {L}. and {S}chwarzinger, {M}. and {S}etbon, {M}. and {L}egeas, {M}. and {L}e {C}ann, {P}. and {F}lahault, {A}. and {C}arrat, {F}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}his study relies on the first available data from the {C}ohorts for {P}andemic {I}nfluenza ({C}o{P}an{F}lu)-{F}rance project, which is part of the {C}o{P}an{F}lu international consortium, aimed at studying individual and collective determinants of pandemic {A}/{H}1{N}1v influenza across different countries by setting up prospective cohorts of households. {T}his primary analysis studies the association between elevated haemagglutination inhibition ({HAI}) antibody titers against {A}/{H}1{N}1v and influenza vaccination (seasonal or pandemic) at entry in the cohort. {I}nclusions began on {D}ecember 4, 2009 and ended on {J}uly 23, 2010. {H}ouseholds were sampled using a random telephonic design in {F}rench general population. {A}ll household members were eligible to the cohort; however the inclusion of a household required the participation of all members. {D}uring the inclusion visits, nurses collected detailed data on subjects as well as blood samples. {A} standard {HAI} technique was adapted to the detection and quantification of antibodies to the 2009 {A}/{H}1{N}1v virus. {G}eometric mean titers ({GMT}s) were calculated for {HAI} assays with the use of generalized estimating equations for interval-censored data, and a "{GMT} ratio' ({GMTR}) was defined as the multiplicative factor applied to the {GMT} in presence of an explanatory variable. {T}his preliminary analysis included 1304 subjects belonging to 544 households. {T}he {GMT} in the population was 35 4 [95% {CI}: 30 1; 41 8]. {T}his {GMT} varied among age classes with values of 52 6 [39 2; 70 6], 28 5 [21 2; 38 3], and 38 3 [33 1; 44 5] for subjects below 15, between 15 and 50, and over 50, respectively. {T}he other factors associated to an elevated {GMT} were previous vaccination by either the pandemic or the seasonal strain and history of influenza-like illness ({ILI}) since the beginning of the epidemic. {I}n pandemic vaccine recipients, the {GMT} decreased after vaccination ({GMTR}: 0 89 [0 81; 0 99]) per month since pandemic vaccination. {T}his study confirms previous findings that age, pandemic influenza vaccination, and history of {ILI} are associated with elevated post-seasonal {GMT}. {T}his study also shows that seasonal influenza vaccination may have contributed to an increase of the {HAI} titer, especially in the elderly. {F}urther analyses in this cohort are needed to confirm and explain these first results. {T}he follow-up of subjects involved in the {C}o{P}an{F}lu-{F}rance cohort will provide data to study the risk factors for infection by the influenza virus.},
  keywords = {{A}ntibodies ; cross-sectional studies ; {F}rance ; hemagglutination ; inhibition tests ; humans ; influenza {A} virus {H}1{N}1 subtype ; risk factors},
  booktitle = {},
  journal = {{I}nfluenza and {O}ther {R}espiratory {V}iruses},
  volume = {5},
  numero = {{S}uppl. 1},
  pages = {180--183},
  ISSN = {1750-2640},
  year = {2011},
  URL = {https://www.documentation.ird.fr/hor/{PAR}00007540},
}