Assessment of anti-HBs level in serum of future healthcare workers in terms of hepatitis B infection prevention

Background
The Hepatitis B Virus (HBV) infection continues to be a global health problem despite existing vaccinations. Healthcare Workers (HCWs) worldwide face serious risks from infection due to their high contact with infectious material. It is estimated that post-vaccination seroprotection is lifelong or at least lasts 20 years by providing circulating antibodies to the surface HBV antigen (HBsAg).

Objectives
The aim of the study was to examine the level of anti-HBs among a group of future HCWs.

Material and methods
The study group consisted of 90 medical students. Blood samples were collected and anti-HBs concentrations were measured by diagnostic test (ELISA kit, Antisurase B‐96 TMBII).

Results
All patients declared they received a mandatory vaccination as a child. A booster dose in the last 10 years was taken by 11.1%. 90% did not know if someone from their surroundings/families suffered from HBV infection. The total average antibody level was 24.93 mIU/mL (range: < 6.76–309.438). There were 56 (62.2%) samples with a very low concentration (< 10 ml mIU/mL), judged as a non-reactive value, and the remaining (34 ppl/37.8%) with a reactive value (range: 10.957–309.438 mIU/mL). Moreover, the obtained concentrations were found to correlate with the time elapsed since the last vaccination, with the result showing a trend towards significance (*p = 0.0571).

Conclusions
The findings suggest that post-vaccination immunity declines over time in most of cases. In case of potential infection, people with a higher risk, like HCWs should have elevated anti-HBs levels for safety reasons. For better prevention and risk stratification in the group of HCWs, periodic examination should be provided.