Haemophilus influenzae type b (Hib) conjugate vaccine is highly effective against invasive disease, reduces Hib nasopharyngeal carriage and produces a strong immune response in healthy children (1). Persistent bacterial airways infection is a driving factor behind neutrophilic asthma and preschool wheeze (PSW). Evidence suggests there are beneficial effects of Hib vaccination to the development and control of preschool asthma (2).
Our aim was to assess the response to primary Hib vaccination in children with PSW. 57 children (20 female) with a median age (range) 3 years (1 ? 5) and diagnosis of PSW had Hib antibody concentration measured.
| History of atopy | 25/57 (43.9%) |
| Family history of atopy | 34/57 (59.6%) |
| Long term azithromycin | 36/57 (63.2%) |
| Moderate/ High dose inhaled corticosteroid | 29/57 (50.9%) |
| admission to paediatric intensive care | 8/57 (14%) |
| Bronchoalveolar lavage (BAL) | 32/57 (56.1%) |
| Positive bacterial culture BAL | 20/32 (62.5%) |
Table 1. Group characteristics
Median (range) Hib antibody concentration was 1.46 mg/L (0.05-12.3) which is lower than reported titres in healthy vaccinated children in this age group (1). Suboptimal response (<1mg/L) was common (40.4%) and was independent of age, sex, atopy, treatment and BAL growth. 14% had very low titres (<0.1 mg/L). Children with neutrophilic BAL inflammation were more likely to have a suboptimal Hib vaccine response compared to those with mixed neutrophilic and eosinophilic picture (OR 3.50, 95% CI 0.472 - 25.902, p=0.212).
Suboptimal response to Hib vaccine is common in children with preschool wheeze. Booster vaccination is likely to be beneficial.
1.Schauer et al. Clinical and Vaccine Immunology 2003
2.Gao Ya-dong et al Allergy 2022