title: Influence of Population Demography and Immunization History on the Impact of an Antenatal Pertussis Program.
abstract: BACKGROUND
  Antenatal pertussis vaccination is being considered as a means to reduce the burden of infant pertussis in low- and middle-income countries (LMICs), but its likely impact in such settings is yet to be quantified.
  
  
  METHODS
  An individual-based model was used to simulate the demographic structure and dynamics of a population with characteristics similar to those of LMICs. Transmission of pertussis within this population was simulated to capture the incidence of infection in (1) the absence of vaccination; (2) with a primary course only (three doses of diphtheria, tetanus, and pertussis vaccines [DTP3] commencing in 1985, 1995, or 2005 at 20%, 50%, or 80% coverage); and (3) with the addition of an antenatal pertussis program.
  
  
  RESULTS
  Modeled annual incidence averaged over the period 2015-2024 reduced with increasing DTP3 coverage, regardless of the year childhood vaccination commenced. Over the same period, the proportion of infants born with passive protection did not change substantially compared with the prevaccination situation, regardless of DTP3 coverage and start year. We found minimal impact of antenatal vaccination on infection in all infants when mothers were eligible for a single antenatal dose. When mothers were eligible for multiple antenatal doses, incidence in infants aged 0-2 months was reduced by around 30%. This result did not hold for the full 0- to 1-year age group, for whom antenatal vaccination did not reduce infection levels.
  
  
  CONCLUSIONS
  While antenatal vaccination could potentially reduce infant mortality in LMICs, broader gains at the population level are likely to be achieved by focusing efforts on increasing DTP3 coverage.
authors.affiliation: Melbourne School of Population and Global Health, University of Melbourne.|Infection and Immunity, Murdoch Childrens Research Institute, Royal Children's Hospital.
authors.forename: Patricia Therese
authors.initials: PT
authors.lastname: Campbell
authors.affiliation: Melbourne School of Population and Global Health, University of Melbourne.|Infection and Immunity, Murdoch Childrens Research Institute, Royal Children's Hospital.|Peter Doherty Institute for Infection and Immunity, University of Melbourne, Parkville, Victoria.
authors.forename: Jodie
authors.initials: J
authors.lastname: McVernon
authors.affiliation: National Centre for Immunisation Research and Surveillance, Children's Hospital at Westmead, New South Wales, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: McIntyre
authors.affiliation: Melbourne School of Population and Global Health, University of Melbourne.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Geard
mesh_terms: D000328:Adult; D000465:Algorithms; D003198:Computer Simulation; D015721:Diphtheria-Tetanus-Pertussis Vaccine / Q000008:administration & dosage / Q000276:immunology*; D005260:Female; D006801:Humans; D007112:Immunity, Maternally-Acquired; D017589:Immunization Programs; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D018811:Maternal Exposure; D008962:Models, Theoretical; D011247:Pregnancy; D011295:Prenatal Care; D011297:Prenatal Exposure Delayed Effects; D014611:Vaccination; D014917:Whooping Cough / Q000453:epidemiology* / Q000517:prevention & control*
chemical_list: D015721:Diphtheria-Tetanus-Pertussis Vaccine
keywords: antenatal vaccination; computer simulation; disease transmission; immunity; pertussis vaccine