title: Molecular analysis of respiratory syncytial virus reinfections in infants from coastal Kenya.
abstract: BACKGROUND
  Individuals are reinfected with respiratory syncytial virus (RSV) repeatedly. The nature of reinfection, in relation to RSV genetic and antigenic diversity, is ill defined and has implications for persistence and vaccine control.
  
  
  METHODS
  We examined the molecular relatedness of RSV causing primary and repeat infections, by phylogenetic analysis of the attachment (G) gene in 12 infants from a birth cohort in rural Kenya, using nasal wash samples collected during a 16-month period in 2002-2003, which spanned 2 successive epidemics.
  
  
  RESULTS
  Six infants were infected during both epidemics, 4 with RSV-A in the first epidemic followed by RSV-B during the second epidemic and 2 with RSV-A during both epidemics, with no significant G gene sequence variability between samples. Two infants were infected and reinfected with different RSV-A strains during the same epidemic. Possible viral persistence was suspected in the remaining 4 infants, although reinfection with the same variant cannot be excluded.
  
  
  CONCLUSIONS
  These are the first data that specifically address strain-specific reinfections in infancy in relation to the primary infecting variant. The data strongly suggest that, following primary infection, some infants lose strain-specific immunity within 7-9 months (between epidemics) and group-specific immunity within 2-4 months (during an epidemic period).
authors.affiliation: Division of Immunity and Infection, University of Birmingham, UK. P.D.Scott@warwick.ac.uk
authors.forename: Paul D
authors.initials: PD
authors.lastname: Scott
authors.forename: Rachel
authors.initials: R
authors.lastname: Ochola
authors.forename: Mwanajuma
authors.initials: M
authors.lastname: Ngama
authors.forename: Emelda A
authors.initials: EA
authors.lastname: Okiro
authors.forename: D
authors.initials: D
authors.lastname: James Nokes
authors.forename: Graham F
authors.initials: GF
authors.lastname: Medley
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Cane
mesh_terms: D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D007223:Infant; D007630:Kenya / Q000453:epidemiology; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D012008:Recurrence; D018357:Respiratory Syncytial Virus Infections / Q000453:epidemiology* / Q000821:virology; D018113:Respiratory Syncytial Virus, Human / Q000145:classification* / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014760:Viral Fusion Proteins / Q000235:genetics
chemical_list: C502275:G glycoprotein, Respiratory syncytial virus; D014760:Viral Fusion Proteins