Médecine néonatale et pédiatrique

Abstrait

Impact of obesity on live attenuated hepatitis A vaccine response in children and young adults

Termpong Dumrisilp

Background: Obesity predisposes chronic inflammatory state that interferes to vaccine response. There are inconclusive results of correlation between obesity and hepatitis A virus (HAV) vaccine-response. There are limited data focusing on live attenuated hepatitis A vaccine. Objective: Our aim was to evaluate the effect of overweight and obesity on the response to live attenu¬ated hepatitis A vaccine in children and young adult. Methods: This was a prospective cohort study conducted at 3 schools, 1 university and 1 obesity clinic at hospital. The subjects aged 7 to 25 years were tested for baseline anti-HAV antibodies and administered 0.5 mL of live attenu¬ated hepatitis A vaccine (MEVAC-A™). Participants with seronegative defined by anti-HAV antibodies (<20 mIU/mL) were divided into three groups according to obesity defined as follows WHO classification. We evaluated immunogenicity and adverse events (AE) after 8-9 weeks from vaccination. Results: A total of 212 subjects completing the study (female: 131, median age (IQR): 13 years (11-16). Of these, 95 subjects (46%) were in overweight/obesity group. All the AE (n=106) were non-serious and most event was myalgia (34%). The seroprotection (≥20 mIU/mL antibody titer after vaccination) rates were 100 %. Post vaccination geometric mean titers of anti-HAV (IU/L) were 451.1 [95%CI: 374.76-543.0] in underweight group, 428.38 [95%CI: 399.61-459.22] in normal weight group and 467.46 [95%CI: 425.01-514.16] in overweight/obesity group. No significant differences in immunogenicity were found between 3 groups (p=0.33). Conclusion: Live attenu¬ated hepatitis A vaccine is safe and highly immunogenic because all of participants were.