Ten Years of Hib Vaccination in Tunisia : Epidemiological Trends and Emerging Challenges

Abstract

Background: Haemophilus influenzae type b (Hib) was historically a leading cause of bacterial meningitis and pneumonia among young children worldwide. Tunisia introduced Hib conjugate vaccination in 2002 as part of the pentavalent vaccine. Ten years after vaccine implementation, 
epidemiological surveillance revealed changing disease patterns and emerging challenges.

Methods: A retrospective, multicenter analysis of national surveillance data was conducted from 2012 to 2022. Laboratory-confirmed cases of invasive 
H. influenzae infections were reviewed. Incidence trends, demographic characteristics, vaccination status, and the distribution of non-b serotypes 
were analyzed.

Results: Hib disease incidence declined by 80% compared with pre-vaccination levels, yet sporadic cases persisted, particularly after 2018. Non-type b strains became increasingly prevalent. Vaccine coverage remained high (>90%) nationally but showed regional disparities. 

Conclusions: The Tunisian Hib vaccination program achieved sustained reduction in invasive Hib disease, but surveillance data indicate the emergence of non-b H. influenzae strains and possible vaccine-related challenges. Continuous monitoring and immunization program strengthening remain essential