Immunological Response to Recombinant Hepatitis B Virus (HBV) Vaccine among Vaccinated Adults in Kaduna South, Nigeria

Aim: The aim of this study was to determine the rate of immunological response to recombinant Hepatitis B Virus (HBV) vaccine among vaccinated residents of Kaduna South Senatorial district.

Materials and Methods: This was a cross-sectional study of 180 consented residents of Kaduna South Senatorial district, Kaduna State who have been vaccinated with HBV vaccines. Systematic sampling technique and written informed consent were used in recruiting subjects for this study. Five (5mls) of venous blood was collected from each subject after filling a structured questionnaire. Sera obtained from 180 subject were qualitatively assayed for HBV markers using SkyTech profile and quantitatively tested for Anti-HBs using ELISA KIT (Enzyme Linked Immunoassay for qualitative and quantitative determination of antibodies to Hepatitis B surface Antigen by DIA.PRO in Italy). The results from the laboratory analysis of the specimens were computed using SPSS version 21.

Results: The results represent 51.7% seropositive of HBsAb among subjects with male having 18.9% and female had 32.8% which statistically showed no significant difference between the groups (χ2 =3.612,P = .43) see Table 1 .In respect to age, 26 – 30years age grouped had the highest sero-conversion rate of 10.0%. This however, was not statistically significant (Table 2) (χ2=5.604, P = .70). For the number of vaccine shots (Table 3) taken, 40.6% of those who completed their vaccination were sero-converted followed by those who took two shots with 4.4% while those who had one shot had 6.7% HBsAb (χ2 =30.665, P< .001). Sero-conversion in relation to the quantity of HBV vaccine with titre values of ≥100IU/ml had 34.6%while ≤ 100IU/ml had 16.1% respectively. The result therefore showed statistically significant difference to the quantity of the vaccine administered at χ2 = 6.98, P = .08. In Table 4.

Conclusion: The findings in the research show that none of the subjects tested positive for Hepatitis B envelope Antigen or Hepatitis B envelop antibody. This could due to prior resolved HBV infection before the onset of vaccination or a resolved HBV infection mid-way into the vaccination process. Low sero-conversion rate was observed which could be due to the inclusion of subjects who failed to complete their vaccination.