Kenya Medical Research Institute, Centre for Geographic Medicine Research-Coast, Kilifi, Kenya.
PLoS One. 2009 Dec 2;4(12):e8088. doi: 10.1371/journal.pone.0008088.
Respiratory syncytial virus (RSV) is the major cause of lower respiratory tract infection in infants. The rate of decay of RSV-specific maternal antibodies (RSV-matAb), the factors affecting cord blood levels, and the relationship between these levels and protection from infection are poorly defined.
A birth cohort (n = 635) in rural Kenya, was studied intensively to monitor infections and describe age-related serological characteristics. RSV specific IgG antibody (Ab) in serum was measured by the enzyme linked immunosorbent assay (ELISA) in cord blood, consecutive samples taken 3 monthly, and in paired acute and convalescent samples. A linear regression model was used to calculate the rate of RSV-matAb decline. The effect of risk factors on cord blood titres was investigated.
The half-life of matAb in the Kenyan cohort was calculated to be 79 days (95% confidence limits (CL): 76-81 days). Ninety seven percent of infants were born with RSV-matAb. Infants who subsequently experienced an infection in early life had significantly lower cord titres of anti-RSV Ab in comparison to infants who did not have any incident infection in the first 6 months (P = 0.011). RSV infections were shown to have no effect on the rate of decay of RSV-matAb.
Maternal-specific RSV Ab decline rapidly following birth. However, we provide evidence of protection against severe disease by RSV-matAb during the first 6-7 months. This suggests that boosting maternal-specific Ab by RSV vaccination may be a useful strategy to consider.
呼吸道合胞病毒（RSV）是婴儿下呼吸道感染的主要原因。母体抗体（RSV-matAb）衰减率、影响脐带血水平的因素以及这些水平与感染保护之间的关系尚未明确。
对肯尼亚农村的一个出生队列（n=635）进行了深入研究，以监测感染情况并描述与年龄相关的血清学特征。通过酶联免疫吸附试验（ELISA）测量脐带血、连续 3 个月的样本以及急性和恢复期的配对样本中的血清 RSV 特异性 IgG 抗体（Ab）。使用线性回归模型计算 RSV-matAb 衰减率。调查了危险因素对脐带血滴度的影响。
肯尼亚队列的 matAb 半衰期计算为 79 天（95%置信区间（CL）：76-81 天）。97%的婴儿出生时带有 RSV-matAb。与在生命早期未发生感染的婴儿相比，随后在早期生活中发生感染的婴儿的抗 RSV Ab 脐带血滴度明显较低（P=0.011）。RSV 感染对 RSV-matAb 衰减率没有影响。
母体特异性 RSV Ab 在出生后迅速下降。然而，我们提供了证据表明 RSV-matAb 在头 6-7 个月内可预防严重疾病。这表明通过 RSV 疫苗接种增强母体特异性 Ab 可能是一种值得考虑的策略。
