BACKGROUND: The minimum number of doses of pneumococcal conjugate vaccine required for protection is not known. We studied the immunogenicity of a reduced schedule in infants and toddlers. METHODS: U.K. infants were given either 2 or 3 doses (at 2 and 4 or 2/3/4 months of age) of a 9-valent pneumococcal conjugate vaccine (9VPCV) followed by boosting at 12 months of age. In a separate study, toddlers (12 months) received 1 or 2 doses (2 months apart) of 9VPCV followed by pneumococcal polysaccharide vaccine at 18 months of age. RESULTS: For infants, serotype-specific IgG geometric mean concentrations were similar post-primary immunization between the groups with both showing avidity maturation and similar booster responses. For toddlers, the primary response to 4 of the 9 serotypes was lower in the 1- compared with the 2-dose group (type 6B, 0.77 versus 7.1; type 14, 4.67 versus 14.98; type 19F, 5.05 versus 7.75; type 23F, 2.48 versus 5.05), although for all serotypes booster responses were similar between groups, and the postprimary responses in the 1-dose group were at least as high as those after infant immunization. CONCLUSIONS: The 2-dose infant priming schedule of 9VPCV is comparable with the 3-dose schedule and may thus be equally protective, whereas 1 dose in toddlers may suffice for a catch-up.
RCT Entities:
BACKGROUND: The minimum number of doses of pneumococcal conjugate vaccine required for protection is not known. We studied the immunogenicity of a reduced schedule in infants and toddlers. METHODS: U.K. infants were given either 2 or 3 doses (at 2 and 4 or 2/3/4 months of age) of a 9-valent pneumococcal conjugate vaccine (9VPCV) followed by boosting at 12 months of age. In a separate study, toddlers (12 months) received 1 or 2 doses (2 months apart) of 9VPCV followed by pneumococcal polysaccharide vaccine at 18 months of age. RESULTS: For infants, serotype-specific IgG geometric mean concentrations were similar post-primary immunization between the groups with both showing avidity maturation and similar booster responses. For toddlers, the primary response to 4 of the 9 serotypes was lower in the 1- compared with the 2-dose group (type 6B, 0.77 versus 7.1; type 14, 4.67 versus 14.98; type 19F, 5.05 versus 7.75; type 23F, 2.48 versus 5.05), although for all serotypes booster responses were similar between groups, and the postprimary responses in the 1-dose group were at least as high as those after infant immunization. CONCLUSIONS: The 2-dose infant priming schedule of 9VPCV is comparable with the 3-dose schedule and may thus be equally protective, whereas 1 dose in toddlers may suffice for a catch-up.
Authors: Paul V Licciardi; Anne Balloch; Fiona M Russell; Robert L Burton; Jisheng Lin; Moon H Nahm; Edward K Mulholland; Mimi L K Tang Journal: J Allergy Clin Immunol Date: 2012-02-02 Impact factor: 10.793
Authors: Susanna Esposito; Susan Tansey; Allison Thompson; Ahmad Razmpour; John Liang; Thomas R Jones; Giuseppe Ferrera; Alessandro Maida; Gianni Bona; Caterina Sabatini; Lorenza Pugni; Emilio A Emini; William C Gruber; Daniel A Scott; Nicola Principi Journal: Clin Vaccine Immunol Date: 2010-04-28
Authors: F M Russell; A Balloch; M L K Tang; J R Carapetis; P Licciardi; J Nelson; A W J Jenney; L Tikoduadua; L Waqatakirewa; J Pryor; G B Byrnes; Y B Cheung; E K Mulholland Journal: Vaccine Date: 2009-07-17 Impact factor: 3.641
Authors: Jo Southern; Ray Borrow; Nick Andrews; Rhonwen Morris; Pauline Waight; Michael Hudson; Paul Balmer; Helen Findlow; Jamie Findlow; Elizabeth Miller Journal: Clin Vaccine Immunol Date: 2008-12-17
Authors: Paul Balmer; Ray Borrow; Jamie Findlow; Rosalind Warrington; Sarah Frankland; Pauline Waight; Robert George; Nick Andrews; Elizabeth Miller Journal: Clin Vaccine Immunol Date: 2007-09-19