摘要
Aim: To study how immunity to Streptococcus pneumoniae normally develops in healthy children. Methods: Ninety two healthy children at 3 - 5, 7 - 9 and 13 - 15 years of age were recruited. No one of the children had previously been given pneumococcal vaccine. Serum was analysed for pooled antigens of the 23 most common pneumococcal polysaccharides with ELISA technique, and results are given in opitical density (OD). A three-level semi-quantitative system was used to assess degree of immunity to Streptococcus pneumoniae . Cut-off levels were OD ≤ 0.7 and OD ≥ 1.3, separating low, intermediate and high degree of immunity. Results: Median values for OD differed significantly between the groups, with OD 0.91, 1.18 and 1.10 respectively (p = 0.004). Levels were lower in the youngest age group, but from age 7-9 years, levels were similar trough out childhood. Twenty six percent of the children in the youngest age-group had a low degree of protection (OD ≤ 0.7) to Streptococcus pneumoniae . Such low levels were uncommon from 7 - 9 years of age, found in only 13% of the children. Conclusion: Protective antibodies to Streptococcus pneumoniae develops mainly during the preschool period. Thereafter, levels are stable throughout childhood up to the age of 15 years.
Aim: To study how immunity to Streptococcus pneumoniae normally develops in healthy children. Methods: Ninety two healthy children at 3 - 5, 7 - 9 and 13 - 15 years of age were recruited. No one of the children had previously been given pneumococcal vaccine. Serum was analysed for pooled antigens of the 23 most common pneumococcal polysaccharides with ELISA technique, and results are given in opitical density (OD). A three-level semi-quantitative system was used to assess degree of immunity to Streptococcus pneumoniae . Cut-off levels were OD ≤ 0.7 and OD ≥ 1.3, separating low, intermediate and high degree of immunity. Results: Median values for OD differed significantly between the groups, with OD 0.91, 1.18 and 1.10 respectively (p = 0.004). Levels were lower in the youngest age group, but from age 7-9 years, levels were similar trough out childhood. Twenty six percent of the children in the youngest age-group had a low degree of protection (OD ≤ 0.7) to Streptococcus pneumoniae . Such low levels were uncommon from 7 - 9 years of age, found in only 13% of the children. Conclusion: Protective antibodies to Streptococcus pneumoniae develops mainly during the preschool period. Thereafter, levels are stable throughout childhood up to the age of 15 years.
基金
supported by grants from Stiftelsen Samariten,Sachsska Barnsjukhuset,Sodersjukhuset,Stockholm,Sweden.
