[Universal immunisation against influenza in paediatrics, yes or no?]

The recommendations on influenza vaccination are not homogeneous between countries, with striking differences between the current recommendations in United States and Europe.

The objective of the study is to determine the efficacy, effectiveness and safety of the current flu vaccine (trivalent inactivated vaccine and adapted to the cold [LAIV] live virus vaccine) in healthy children, and to try and answer the following question: universal immunization against influenza in Paediatrics, yes or no?

A scheme of work based on the five standard steps of evidence or science-based medicine was used: 1) question, 2) search, 3) valuation, 4) applicability and 5) adequacy.

Nine systematic reviews, published between 2005 and 2012, were selected that answered our clinical question, and which included the best available information (randomised clinical trials, cohort studies and case studies).

The flu vaccine in childhood has the right cost - benefit - risk relationship. In all systematic reviews the efficacy of the flu vaccine varied between 58%-65%, and effectiveness between 28%-61%. Both efficacy and effectiveness increase with age, and there are limited studies showing sufficient evidence in children < 2 years. There are further areas to develop: more and better clinical trials on influenza vaccines in infants from 6 to 23 months; further research to achieve better influenza vaccines (addition of adjuvants, higher doses in children between 6 and 23 months, and study the LAIV vaccine in children between 6 and 23 months); and improvement in the prediction of vaccine strains responsible for the outbreak.