The General Directorate of Health contacted the High Authority for Health (HAS) in January 2022 to assess the interest of vaccination against seasonal influenza in children and adolescents with no comorbidities.
Each year, seasonal flu affects 2 to 6 million people in France and causes an average of 9,000 deaths. Currently, influenza vaccination is recommended for people at risk of severe illness. Children without comorbidity are not included in these recommendations, but this vaccination is already recommended in several countries such as the United Kingdom, Spain or Austria to limit the health and organizational impact of the disease.
HAS examined the impact of influenza on public health, the vaccination coverage of people at risk, the availability and effectiveness of vaccines, as well as the expected impact of the vaccination of children and adolescents. The studies reviewed showed that seasonal influenza vaccines are effective and well tolerated in children aged 2 to 17 years without comorbidities.
Cochrane reviews have concluded that seasonal influenza vaccines are effective in children without comorbidities, with vaccine efficacy of 78% for live attenuated vaccines and 64% for inactivated vaccines. Available data on the efficacy of vaccination against acute otitis media are limited or inconclusive. There are few data on the effectiveness of vaccination against hospitalizations or deaths, especially in children under 2 years of age. The effectiveness of vaccines varies between studies, flu seasons and countries.
Live attenuated vaccines are more effective than inactivated vaccines in preventing the number of laboratory-confirmed influenza cases, with an influenza hazard ratio (inactivated vs live attenuated) of 0.52 (95% CI: 0.32-0, 82). A Finnish cohort reported vaccine efficacy against all types of influenza of 68% (95% CI: 58%-75%) for Fluenz Tetra and 71% (95% CI: 56%-80%) for Vaxigrip Tetra. Only one review with meta-analysis has been published on the indirect efficacy of vaccination, which showed an efficacy of 33% in people living in the close circle of a vaccinated child.
In France, the five existing vaccines against seasonal influenza (Fluarix Tetra®, Vaxigrip Tetra®, Influvac Tetra®, Flucelvax® and Fluenz Tetra®) show no particular signal of tolerance in children. These vaccines are also considered safe in children in European and global data.
HAS recommends that vaccination against seasonal influenza be offered each year to children without comorbidities aged 2 to 17 years old, without it being made compulsory. She issued a preferential recommendation for the vaccine administered intranasally, called Fluenz Tetra®, which has better acceptability in children. Children under two years of age are not included in this recommendation.
The HAS estimates that this vaccination in children aged 2 to 17 would limit the spread of the disease within the population and among the elderly. Children under the age of 15 are over-represented among cases of flu syndrome seen in community medicine consultations and in the emergency room.
HAS has stressed the need to reimburse seasonal flu vaccines for children aged 2 to 17 so that any parent who wishes can have their child vaccinated against the flu without financial impediment. She also insisted on the importance of supporting this recommendation with an information system for health professionals and parents.
See the HAS opinion