A Case Series of T Cell and Cytokine Immune Responses in Six Health Care Workers Vaccinated with a Recombinant Hepatitis B DNA Vaccine

  • Tracy Naomi Phiri University of Zambia, School of Health Sciences https://orcid.org/0000-0001-7110-3347
  • Caroline Chisenga The University of Zambia, School of Health Sciences
  • Michelo Simuyandi The University of Zambia, School of Health Sciences
  • Kalo Musukuma The University of Zambia, School of Health Sciences
  • Luiza Hatyoka The University of Zambia, School of Health Sciences
  • Owen Ngalamika University of Zambia, School of Medicine
  • Moses Sakala University of Zambia, School of Medicine
  • Roma Chilengi Center for Infectious Disease Research in Zambia (CIDRZ)
  • Sody M Munsaka The University of Zambia, School of Health Sciences
Keywords: Health care workers, Hepatitis B, Vaccination, HBsAg-specific T cells, cytokines, anitbodies


Background: The vaccination coverage among health care workers (HCWs) in Zambia is low. Most vaccinated HCWs do not know how they responded because they self-vaccinate and/or do not receive all recommended doses. Hence, we aimed to assess T cell and cytokine responses, hepatitis B surface antigen (HBsAg) antibodies (anti-HBs) in HCWs in Kalulushi, Zambia after vaccination with a recombinant hepatitis B vaccine from the serum Institute of India. Methods and Materials: Peripheral blood mononuclear cells (PBMCs) collected from 6 vaccinated HCWs (cases) who had received at least 2 doses of the vaccine were stimulated with the HBsAg. Using flow cytometry, the concentrations of tumor necrosis factor, interleukin 10, interleukin 6, and interleukin 2 were measured in the supernatant while HBsAg-specific CD4+ and CD8+ effector and memory were measured using the cell pellet. Using plasma, anti-HBs, HBsAg, the Hepatitis B core antigen (HBcAg) and antibodies against the HBcAg (Anti-HBc) were tested using the enzyme-linked immunosorbent assays and data were summarised descriptively. Results: Four of our cases were male, all had a median age and BMI of 32 [IQR 29-44] years and 23.1 [IQR 21.1-27.6] kg/m2 respectively. The anti-HBs in all 6 cases increased after each dose and in 5 of the cases, either the HBsAg-specific effector CD4+ or effector CD8+, or memory CD4+, and/or memory CD8+ responses after doses 1, 2 and 3 were detectable. Despite having anti-HBs of 0IU/mL at baseline, participant 2 had 18.6% and 45.5% CD4+ and CD8+ memory after dose 1 respectively. Case 1 had the highest HBsAg-specific TNF (244.81pg/mL) after dose 2 while case 3 also had the highest HBsAg-specific IL-6 (69.91pg/mL) after dose 2 and were both HIV+. Additionally, only the 3 participants who were HIV+ had HBsAg-specific effector and memory CD8+ cells after vaccination. Conclusion: From our case series, we demonstrate that HBV vaccines are immunogenic in HCWs in Zambia. They elicit at least one HBsAg-specific immune response after one dose. We recommend vaccinating all HCWs and more similar studies to help understand HBV-specific immune responses in vaccines better.