Prevalence of immune non-response to Hepatitis B virus vaccine among secondary school students in Kumi district, Eastern Uganda

Abstract

Background: Hepatitis B virus is still a silent killer disease in Ugandan communities, particularly in high burdened regions. Despite Government initiative for mass vaccination program for those areas, there has been uncertainty of the non- response rate to HBV vaccine administered to secondary school-going students in Kumi District, Eastern Uganda. Therefore, this study determined the prevalence of non- response to HBV vaccine and associated factors that may influence the non- responsiveness to the students in Kumi district. Methods: This was a cross-sectional study conducted from January to March 2021. The study involved 198 secondary school students aged 18 – 20 years from Wiggins SS and Atutur Seed SS, Kumi District. Whole Blood samples were collected by venipuncture from school students, centrifuged to obtain serum. Serum samples were transferred into cryovails. HBs Ag testing was done using RDTs. The rest of the remaining serum samples were stored in the fridge before shipment to BMK Medical laboratory. Tittering was done to determine levels of Anti-HBs. A structured case report form was used to collect demographic data on associated factors. Results: The mean value of anti-HBs titer of seropositive participants who completed all recommended three shots was significantly higher than those who received either one or two shots (p=0.0003 and p=0.0141respectively). Only 58.59% of study participants completed all three recommended doses with more female completing compared to the male counterparts (58 and 57 respectively). 10 out of 198 participants had HBV infection after vaccination; number of chronic infections was 20% of the total infections while acute infection was 80% of the total infection. 94.44% of our participants still have protective anti-HBS antibody levels (≥10 m UI/mL) and one third (33.3%) still had anti-HBs antibody titers ˃500 m UI/mL. 14.15% overall of participants were non-responders to vaccination and 8.59% were break through infections after vaccination. There was no significant difference between mean value of serum concentration of ant-HBs titer for male versus female across 1 dose, 2 doses and 3 doses (p=0.5333, p=0.5012 p=0.5701 respectively). Conclusion: Third HBV vaccine shot is very important in boosting immune response as evidenced by higher titer levels of individuals who completed all three doses. Non-response rate to HBV vaccine in this study is high compared to most studies done elsewhere which has bearing to the efficacy and potency of this vaccine.