Persistence of Anti-HBs Among Palestinian Medical Students After 18 - 22 Years of Vaccination: A Cross-Sectional Study

Background: hepatitis b infection is a global public health problem affecting various sectors in the society. vaccination is the first line measure to prevent the disease. objectives: to assess the persistence of anti-hbs marker among medical students after 18 - 22 of vaccination as an indicator for hepatitis b virus vaccine efficacy. patients and methods: in this study, 249 palestinian medical students vaccinated at birth, 1, and 6 months of age using engerix™-b starting from 1992 were studied. about 58% (144/249) of the students were palestinians holding israeli citizenship, while 42% (105/249) were palestinians from the west bank. students were tested serologically for anti-hbs, as a marker for vaccine-induced immunity. results: over 75% (188/248) of students had levels of anti-hbs greater than 10 miu/ml indicating immunity and protection. five cases had positive results for anti-hbc indicating exposure to hbv infection; however, none of these cases showed any sign of hbv-dna indicating effective clearance of the virus by the vaccine. around 57% of the study group had anti-hbs level of 100 - 1000 miu/ml. no significant association was found between anti-hbs level and age, sex, locality and level of anti-hbc (p > 0.05). the students were aware of different aspects of hepatitis b infection regarding the virus, symptoms, prevention and mode of transmission. conclusions: the palestinian and israeli official policies to give a booster dose for risk groups like medical students at anti-hbs level below 10 miu/ml should continue to ensure absolute protection. the currently-used vaccine and its time program cleared virus from students believed to have been exposed to the virus during their lifetime.