Seasonal influenza immunization in early infancy?

Seasonal influenza is an important public health and medical challenge. Vaccination against influenza is recognized worldwide as the main strategy for prevention and control. The findings of meta-analyses, however, suggest that efficacy and effectiveness of influenza vaccines, both in people aged 65 years or older [1] and in children, are lower than believed [2]. These findings were recently confirmed, even if mitigated (only) a little, by an additional meta-analysis. This recent study assessed efficacy and effectiveness of licensed influenza vaccines in the USA with sensitive and highly specific diagnostic tests used to confirm influenza [3]. Findings show that in healthy children influenza vaccines have a very variable efficacy (vaccine effects on lab-confirmed influenza) and effectiveness (prevention of influenza-like illness). Available safety data are scant, particularly for inactivated vaccines in younger children [2]. In such a context, when the seasonal periods for influenza arrive, questions concerning who should receive the influenza vaccine are raised among health operators and lay people worldwide. Pediatricians, parents, and caregivers of infants and children in particular, are doubtful as to whether to recommend or accept influenza immunization of children or not [4], also because in children the infection is usually self-limiting without complications, though the risk is higher in those aged less than 6 months [5]. In 2010, the Advisory Committee on Immunization Practices (ACIP) established the first recommendation for a national, universal seasonal influenza vaccination in the USA [6]. Vaccination every year is recommended by ACIP with trivalent inactivated vaccine (TIV) for all individuals aged 6 months or older, or with live attenuated influenza vaccine (LAIV) for healthy, non-pregnant people aged 2-49 years. Up until now only a few countries (i.e.,