Flu and flu vaccines. Present and Future

Approximately two out of 10 children get flu every year. Children are more susceptible to influenza infection contributing to spread the disease in the home and school-setting, by eliminating larger amount of virus during longer period than adults. The most common complications include otitis media, tracheobronchitis, laryngotracheitis, bronchiolitis and bronchitis, most commonly seen in naïve patients. The more severe complication is viral pneumonia, more frequent in infections by influenza A virus. Influenza causes health services burden, particularly in pediatric primary health care, having impact on mortality rates. In the United States during the 2010-11 epidemic there were 115 deaths in children, of whom only 23% were vaccinated. United States and Canada have implemented the recommendation on universal vaccination with particular emphasis on children, in Europe this occurs only in the UK. Currently different types of inactivated virus vaccines are marketed in Spain. Attenuated virus vaccines are used in the United States and Russia. Vaccines with live attenuated influenza virus have been more effective in children <4 years because that population has had less prior exposure to influenza than adults. Most inactivated influenza vaccines are made of complete or split virion. Recent research establishes the possibility of using adjuvanted vaccines in children. Also this research includes quadrivalent vaccines that protect against both lineages of B viruses that can circulate every year. Influenza vaccination of children is a medical necessity not properly covered in Spain. Seasonal epidemics have shown that influenza vaccination of children have a protective effect on other vulnerable groups. While scientific consensus for universal children vaccination is achieved, it is the responsibility of the pediatrician to strongly recommend influenza vaccination of children and adolescents with underlying diseases as well as their household contacts.