Goldblatt David, Southern Jo, Ashton Lindsey, Richmond Peter, Burbidge Polly, Tasevska Juliana, Crowley-Luke Annette, Andrews Nick, Morris Rhonwen, Borrow Ray, Cartwright Keith, Miller Elizabeth
Institute of Child Health, University College London, UK.
Pediatr Infect Dis J. 2006 Apr;25(4):312-9. doi: 10.1097/01.inf.0000207483.60267.e7.
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.
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.
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.
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.
尚不清楚提供保护所需的肺炎球菌结合疫苗的最小剂量数。我们研究了婴幼儿简化接种程序的免疫原性。
英国婴儿在2月龄和4月龄或2/3/4月龄时接种2剂或3剂9价肺炎球菌结合疫苗（9VPCV），并在12月龄时加强接种。在另一项研究中，幼儿（12月龄）间隔2个月接种1剂或2剂9VPCV，并在18月龄时接种肺炎球菌多糖疫苗。
对于婴儿，两组在初次免疫后血清型特异性IgG几何平均浓度相似，均显示亲和力成熟且加强反应相似。对于幼儿，1剂组对9种血清型中4种的初次反应低于2剂组（6B型，0.77对7.1；14型，4.67对14.98；19F型，5.05对7.75；23F型，2.48对5.05），尽管所有血清型的加强反应在两组间相似，且1剂组的初次反应至少与婴儿免疫后的反应一样高。
9VPCV的2剂婴儿初始接种程序与3剂程序相当，因此可能具有同等的保护作用，而幼儿接种1剂可能足以用于补种。
