Prevalence of hepatitis B surface antibody among previously vaccinated healthcare workers in Tashkent, Uzbekistan

Healthcare workers (HCW) have high occupational risk for hepatitis B and Uzbekistan held two HCW vaccination campaigns in 2015 and 2022. Hepatitis B antibody testing (anti-HBs) after Hepatitis B (HepB) vaccination is recommended by the U.S. CDC and WHO for HCW, but Uzbekistan does not have such a policy. In 2023, we randomly selected HCW from the campaign registries. Participants who agreed were interviewed at their workplaces. Vaccination doses were self-reported. Testing for hepatitis B surface antigen (HBsAg), Total hepatitis B core antibody (anti-HBc), and anti-HBs were concurrently performed. We used multivariable Poisson regression to assess factors associated with anti-HBs ≥10 mIU/mL. Of 334 participants, 205 were vaccinated in 2015 and 129 in 2022. Median age was 40 years (interquartile range 35-49 years), and 87% were female. Most (71%) reported having completed the three doses, 21% two doses and 7% one dose. Testing revealed that 5% had an active HBV infection, 4% had a resolved infection, and 91% had detectable vaccine-derived antibodies. Among those (<i>n</i> = 303), 71% had anti-HBs ≥10 mIU/mL. For those who reported receiving 1, 2, and 3 doses, protective titers were 59%, 70%, and 72%, respectively. Protective titers were lower for HCW that worked in clinics versus hospitals (aPR = 0.92, CI: 0.87-0.98, <i>p</i> = .01) adjusting for age, dose number and presence of chronic conditions. Strategies to improve completion of the 3-dose series and policies for post-vaccination immunity testing 1-2 months after completion of the 3-dose HepB series could help identify workers who may require revaccination or are currently infected.