@article{fdi:010084383,
  title = {{I}ndirect effects of 13-valent pneumococcal conjugate vaccine on pneumococcal carriage in children hospitalised with acute respiratory infection despite heterogeneous vaccine coverage : an observational study in {L}ao {P}eople's {D}emocratic {R}epublic},
  author = {{C}han, {J}. and {L}ai, {J}. {Y}. {R}. and {N}guyen, {C}. {D}. and {V}ilivong, {K}. and {D}unne, {E}. {M}. and {D}ubot {P}{\'e}r{\`e}s, {A}udrey and {F}ox, {K}. and {H}inds, {J}. and {M}oore, {K}. {A}. and {N}ation, {M}. {L}. and {P}ell, {C}. {L}. and {X}euatvongsa, {A}. and {V}ongsouvath, {M}. and {N}ewton, {P}. {N}. and {M}ulholland, {K}. and {S}atzke, {C}. and {D}ance, {D}. {A}. {B}. and {R}ussell, {F}. {M}. and {P}neu{CAPTIVE} {L}ao {PDR} {R}esearch {G}roup},
  editor = {},
  language = {{ENG}},
  abstract = {{I}ntroduction {E}mpiric data on indirect (herd) effects of pneumococcal conjugate vaccines ({PCV}s) in settings with low or heterogeneous {PCV} coverage are limited. {T}he indirect effects of {PCV}, which benefits both vaccinated and non-vaccinated individuals, are mediated by reductions in vaccine-type ({VT}) carriage (a prerequisite for disease). {T}he aim of this study among hospitalised children in {L}ao {P}eople's {D}emocratic {R}epublic ({L}ao {PDR}) is to determine the effectiveness of a 13-valent {PCV} ({PCV}13) against {VT} pneumococcal nasopharyngeal carriage (direct effects) and the association between village-level {PCV}13 coverage and {VT} carriage (indirect effects). {M}ethods {P}neumococcal nasopharyngeal carriage surveillance commenced in {D}ecember 2013, shortly after {PCV}13 introduction ({O}ctober 2013). {W}e recruited and swabbed children aged 2-59 months admitted to hospital with acute respiratory infection. {P}neumococci were detected using lyt{A} quantitative real-time {PCR} and serotyped using microarray. {PCV}13 status and village-level {PCV}13 coverage were determined using written immunisation records. {A}ssociations between both {PCV}13 status and village-level {PCV}13 coverage and {VT} carriage were calculated using generalised estimating equations, controlling for potential confounders. {R}esults {W}e enrolled 1423 participants and determined {PCV}13 coverage for 368 villages (269 863 children aged under 5 years). {B}y 2017, median village-level vaccine coverage reached 37.5%, however, the {IQR} indicated wide variation among villages (24.1-56.4). {B}oth receipt of {PCV}13 and the level of {PCV}13 coverage were independently associated with a reduced odds of {VT} carriage: adjusted {PCV}13 effectiveness was 38.1% (95% {CI} 4.1% to 60.0%; p=0.032); and for each per cent increase in {PCV}13 coverage, the estimated odds of {VT} carriage decreased by 1.1% (95% {CI} 0.0% to 2.2%; p=0.056). {A}fter adjustment, {VT} carriage decreased from 20.0% to 12.8% as {PCV}13 coverage increased from zero to 60% among under 5. {C}onclusions {D}espite marked heterogeneity in {PCV}13 coverage, we found evidence of indirect effects in {L}ao {PDR}. {I}ndividual vaccination with {PCV}13 was effective against {VT} carriage.},
  keywords = {vaccines ; epidemiology ; {LAOS}},
  booktitle = {},
  journal = {{BMJ} {G}lobal {H}ealth},
  volume = {6},
  numero = {6},
  pages = {e005187 [13 ]},
  ISSN = {2059-7908},
  year = {2021},
  DOI = {10.1136/bmjgh-2021-005187},
  URL = {https://www.documentation.ird.fr/hor/fdi:010084383},
}