There is no clear direction of causality as children with low birth weight have more respiratory infections compared to a control population (Chan et al, 1989), while it is recognized that CRP boosts the innate immune response to bacteria (Ng et al., 2007), with particular activity against Streptococcus pneumonia (Thomas‐Rudolph et al., 2007). This evidence concerns the gene CRP and streptococcal pneumonia.