Seasonal influenza immunization in infants younger than 6 months, too?

Key words: Influenza vaccines, Vaccination, Newborn, Infant, Efficacy

Vaccination against seasonal influenza is recognized worldwide as the main strategy for prevention and control. However, efficacy and effectiveness of influenza vaccines, both in people aged ≥65 years and in children, are lower than believed. 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. The majority of countries continues to apply World Health Organization recommendations that suggest vaccinating only children older than 6 months of age with certain coexisting conditions (chronic heart or lung diseases, metabolic or renal disease, chronic neurological conditions, or immunodeficiencies) through strategies that involve an active promotion of the vaccine. Currently, this vaccination is not recommended in any country for healthy, preterm, or low birth weight infants, even if they have chronic diseases that are contemplated by immunization strategies for infants ≥ 6 months. Based on scant evidence of efficacy and the wide methodological differences between the only three available studies, any attempt to suggest immunizing infants < 6 months of age against seasonal influenza would be arbitrary and unethical. Therefore, this population can be protected by limiting their exposure to influenza through both educational interventions targeting health care workers, family members, caregivers, and all individuals who reside with newborns, in particular ill ones, and “cocoon” immunization strategies immunizing all individuals who come into contact with infants.