evidence: The authors carefully concluded that "DTP immunisation was not a significant factor in the occurrence of SIDS" [29]. [...] DTP immunisation is inversely associated with SIDS mortality on the population level. The current findings may strengthen parents’ confidence in the benefit of DTP immunisation, especially as they are supported by the results of two meta-analyses [11,12]. As a public health measure, it is important to emphasise the need for timely immunisation in accordance to the existing schedule. Although confounding and the ecological fallacy due to the use of aggregate data cannot be excluded further research on potential underlying mechanisms of the association between SIDS and immunisation is warranted. [...] Carvajal A, Caro-Paton T, Martin De Diego I, Martin Arias LH, Alvarez Requejo A, Lobato A. [DTP vaccine and infant sudden death syndrome. Meta-analysis]. Med Clin (Barc). 1996;106(17):649–52.