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Invasive Haemophilus influenzae infections in France. 2025 overview.
Published on March 26, 2026
Updated on March 26, 2026
Key points
PDF 0.39 MB
https://www.santepubliquefrance.fr/...-haemophilus-influenzae-en-france.-bilan-2025
Invasive Haemophilus influenzae infections in France. 2025 overview.
Published on March 26, 2026
Updated on March 26, 2026
Key points
- Invasive Haemophilus influenzae infections have been steadily increasing since the early 2000s. The highest incidence rates are observed in infants and the elderly.
- Non-encapsulated strains are predominant in the elderly (85% of cases in 2025) while in children under 5 years of age, encapsulated strains are more frequent, notably serotype b (58% of cases in 2025) and serotype a (17% of cases in 2025).
- Vaccination against Hib has been mandatory for infants since 2018. Vaccination coverage for the three doses of hexavalent vaccines has been estimated at 96% at the age of 2 years in children born between 2018 and 2021.
- Despite this high vaccination coverage, the number of cases of invasive Hib infection in children under 5 years of age increased during the period 2018-2024.
- In 2025, the increase was even more pronounced, particularly from October 2025 onwards. The National Reference Centre for Meningococci and Haemophilus influenzae confirmed 62 cases of invasive Hib infections in children under 5 years of age in 2025, compared to 34 cases in 2024, representing an 82% increase. By comparison, in 2018-2019, fewer than 15 cases were reported annually.
- A slight increase has also been observed since 2020 for serotype a, although the number of cases remains lower than those of serotype b.
- The epidemiological situation shows that Hib continues to circulate at a low level in the population, with a marked seasonality in the fall. The majority of cases of invasive Hib infection occur in children under one year of age, confirming the higher risk in the first year of life.
- The risk of severe Hib infection is particularly high for infants in their first year of life who are unvaccinated or have not yet completed their vaccination schedule.
- As in previous years, and given the very high levels of vaccination coverage, the observed cases occurred primarily in children who were up-to-date with their vaccinations (84% of cases aged 6 to 11 months and 81% of cases aged 12 months and older). Thirteen vaccine failures were identified in 2025, but this represents a minority of events compared to the number of children vaccinated (approximately 5 events per million children vaccinated).
- These data raise questions about current vaccine-induced immunity against Hib in children. They prompt further studies to evaluate the efficacy and duration of protection of the currently recommended infant vaccination schedule.
PDF 0.39 MB
https://www.santepubliquefrance.fr/...-haemophilus-influenzae-en-france.-bilan-2025