title: Immunological effect of administration of sequential doses of Haemophilus influenzae type b and pneumococcal conjugate vaccines in the same versus alternating limbs in the routine infant immunisation schedule: an open-label randomised controlled trial.
abstract: BACKGROUND
  The use of different limbs for the administration of sequential doses of an intradermal rabies vaccine was shown to result in reduced vaccine immunogenicity. We aimed to assess whether this phenomenon also occurs with routine infant vaccines.
  
  
  METHODS
  In this open-label, randomised, controlled study, eligible healthy infants 6-12 weeks of age recruited through five clinical trials units (four in the UK and one in Malta) were randomly assigned in a 1:1 ratio to two vaccination groups: consistent limb or alternating limb. Infants in the consistent limb group received the diphtheria-tetanus-acellular pertussis-inactived polio-Haemophilus influenzae type b combined vaccine (DTaP-IPV-Hib) at 2, 3, and 4 months of age, and the pneumococcal conjugate vaccine (PCV13) at 2, 4, and 12 months, all administered to the right leg. Infants in the alternating limb group received DTaP-IPV-Hib in the left leg at 2 months and in the right leg at 3 and 4 months; and PCV13 in the left leg at 2 months, in the right leg at 4 months, and in the left arm at 12 months. All infants in both groups received the combined H influenzae type b and capsular group C Neisseria meningitidis tetanus toxoid conjugate vaccine (Hib-MenC-TT), administered in the left leg at 12 months. Randomisation was achieved by randomly generated codes, with permuted block size of 30, and was stratified by study site. Group allocation was not masked from study staff and parents of participants after enrolment, but group allocation was masked from laboratory staff assessing blood samples. The current study was a prespecified secondary objective of a parent phase 4 trial that assessed the induction of immunity following varying schedules of vaccination with glyco-conjugate capsular group C Neisseria meningitidis (Men C) vaccines in infancy. The objective of the current study was to compare the immunogenicity and reactogenicity of vaccines delivered in either consistent or alternating limbs. Immunogenicity was assessed by comparing serum IgG geometric mean concentrations at 5, 12, 13, and 24 months, analysed per protocol. This study is registered with ClinicalTrials.gov, number NCT01129518.
  
  
  RESULTS
  Between July 5, 2010, and Aug 1, 2013, we enrolled 509 infants and randomly allocated them to the consistent limb group (n=254) or the alternating limb group (n=255). Anti-H influenzae type b anti-polyribosylribitol phosphate IgG geometric mean concentrations were lower in the consistent limb group than in the alternating limb group at 5 months (consistent limb 0·41 μg/mL [95% CI 0·31-0·54] vs alternating limb 0·61 μg/mL [0·45-0·82]; p=0·0268) and at 12 months (0·35 μg/mL [0·28-0·43] vs 0·50 μg/mL [0·40-0·62]; p=0·0136). Anti-tetanus toxoid antibody IgG geometric mean concentrations were lower in the consistent limb group (1·63 IU/mL [95% CI 1·40-1·90]) than in the alternating limb group (2·30 IU/mL [1·97-2·68]) at 13 months (p=0·0008) and at 24 months (0·44 IU/mL [0·37-0·52] vs 0·61 IU/mL [0·51-0·73]; p=0·0074). Anti-pneumococcal IgG geometric mean concentrations were similar between both groups at all timepoints. The proportions of participants who had adverse events did not differ between the two groups.
  
  
  CONCLUSIONS
  Use of different (alternating) limbs for sequential doses of routine infant vaccines does not reduce, and might enhance, immunogenicity. The underlying mechanism for this finding warrants further research.
  
  
  BACKGROUND
  NIHR Oxford Biomedical Research Centre and GlaxoSmithKline Biologicals.
authors.affiliation: Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and NIHR Oxford Biomedical Research Centre, Oxford, UK. Electronic address: mildred.iro@paediatrics.ox.ac.uk.
authors.forename: Mildred A
authors.initials: MA
authors.lastname: Iro
authors.affiliation: Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and NIHR Oxford Biomedical Research Centre, Oxford, UK.
authors.forename: Ameneh
authors.initials: A
authors.lastname: Khatami
authors.affiliation: Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and NIHR Oxford Biomedical Research Centre, Oxford, UK.
authors.forename: Andrew S J
authors.initials: AS
authors.lastname: Marshall
authors.affiliation: Malta Children's Vaccine Group, Mater Dei Hospital, Msida, Malta.
authors.forename: David
authors.initials: D
authors.lastname: Pace
authors.affiliation: Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK.
authors.forename: Merryn
authors.initials: M
authors.lastname: Voysey
authors.affiliation: Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and NIHR Oxford Biomedical Research Centre, Oxford, UK.
authors.forename: Jennifer
authors.initials: J
authors.lastname: McKenna
authors.affiliation: Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and NIHR Oxford Biomedical Research Centre, Oxford, UK.
authors.forename: Danielle
authors.initials: D
authors.lastname: Campbell
authors.affiliation: Malta Children's Vaccine Group, Mater Dei Hospital, Msida, Malta.
authors.forename: Simon
authors.initials: S
authors.lastname: Attard-Montalto
authors.affiliation: Bristol Children's Vaccine Centre, University Hospitals Bristol NHS Foundation Trust and University of Bristol, UK.
authors.forename: Adam
authors.initials: A
authors.lastname: Finn
authors.affiliation: Bristol Children's Vaccine Centre, University Hospitals Bristol NHS Foundation Trust and University of Bristol, UK.
authors.forename: Catherine
authors.initials: C
authors.lastname: White
authors.affiliation: NIHR Wellcome Trust Clinical Research Facility, University Hospital Southampton NHS Foundation Trust and Faculty of Medicine, University of Southampton, Southampton, UK.
authors.forename: Saul N
authors.initials: SN
authors.lastname: Faust
authors.affiliation: Vaccine Institute, St Georges, University of London, London, UK.
authors.forename: Alison
authors.initials: A
authors.lastname: Kent
authors.affiliation: Vaccine Institute, St Georges, University of London, London, UK.
authors.forename: Paul T
authors.initials: PT
authors.lastname: Heath
authors.affiliation: NIHR Wellcome Trust Clinical Research Facility, University Hospital Southampton NHS Foundation Trust and Faculty of Medicine, University of Southampton, Southampton, UK.
authors.forename: Emma
authors.initials: E
authors.lastname: MacLeod
authors.affiliation: Vaccine Evaluation Unit, Public Health England, Public Health, Laboratory, Manchester, UK.
authors.forename: Elaine
authors.initials: E
authors.lastname: Stanford
authors.affiliation: Vaccine Evaluation Unit, Public Health England, Public Health, Laboratory, Manchester, UK.
authors.forename: Helen
authors.initials: H
authors.lastname: Findlow
authors.affiliation: Vaccine Evaluation Unit, Public Health England, Public Health, Laboratory, Manchester, UK.
authors.forename: Rachael
authors.initials: R
authors.lastname: Almond
authors.affiliation: Vaccine Evaluation Unit, Public Health England, Public Health, Laboratory, Manchester, UK.
authors.forename: Xilian
authors.initials: X
authors.lastname: Bai
authors.affiliation: Vaccine Evaluation Unit, Public Health England, Public Health, Laboratory, Manchester, UK.
authors.forename: Ray
authors.initials: R
authors.lastname: Borrow
authors.affiliation: Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and NIHR Oxford Biomedical Research Centre, Oxford, UK.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Snape
authors.affiliation: Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and NIHR Oxford Biomedical Research Centre, Oxford, UK.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Pollard
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood*; D015721:Diphtheria-Tetanus-Pertussis Vaccine / Q000008:administration & dosage* / Q000276:immunology*; D005121:Extremities; D005260:Female; D018073:Haemophilus Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D019741:Haemophilus influenzae type b / Q000276:immunology*; D064368:Healthy Volunteers; D006801:Humans; D007115:Immunization Schedule; D007074:Immunoglobulin G / Q000097:blood; D007223:Infant; D008297:Male; D008319:Malta; D009345:Neisseria meningitidis / Q000276:immunology*; D022242:Pneumococcal Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D011054:Poliovirus Vaccine, Inactivated / Q000008:administration & dosage* / Q000276:immunology*; D013745:Tetanus Toxoid / Q000008:administration & dosage / Q000276:immunology; D016896:Treatment Outcome; D006113:United Kingdom; D018074:Vaccines, Conjugate / Q000008:administration & dosage / Q000276:immunology
chemical_list: C538862:13-valent pneumococcal vaccine; D000907:Antibodies, Bacterial; D015721:Diphtheria-Tetanus-Pertussis Vaccine; D018073:Haemophilus Vaccines; C527605:Hib-MenCY-TT vaccine; D007074:Immunoglobulin G; D022242:Pneumococcal Vaccines; D011054:Poliovirus Vaccine, Inactivated; D013745:Tetanus Toxoid; D018074:Vaccines, Conjugate; C541234:diphtheria-tetanus-five component acellular pertussis-inactivated poliomyelitis -Haemophilus influenzae type b conjugate vaccine