Hepatitis B virus (HBV) infection remains a major global health concern, with the World Health Organization (WHO) estimating approximately 820,000 deaths annually, primarily due to cirrhosis and hepatocellular carcinoma1. In India, HBV prevalence ranges from 3-4%, classifying it as an intermediate endemic region where chronic carriers contribute to increased occupational risks for healthcare workers (HCWs) and medical students exposed to blood and bodily fluids2.

The standard HBV vaccination regimen—three doses administered over six months—induces protective antibody levels (anti-HBs ≥10 IU/mL) in over 90% of healthy adults, offering robust initial immunity3. However, studies suggest this protection wanes over time, raising concerns about long-term immunity, particularly in high-risk groups. A study among Indian HCWs and medical students observed a decline in protective antibody levels from 94.1% within five years post- vaccination to 72.7% after ten years, indicating a potential vulnerability that may need for booster doses4. Similarly, research in South India found that while 96.5% of HCWs initially maintained seroprotective levels, antibody titers declined over time, with factors such as age, number of doses, and time since last vaccination influencing seroprotection outcomes5.

The necessity of routine booster doses remains debatable due to conflicting evidence. Some studies argue that immunological memory persists even when antibody levels fall below the protective threshold, suggesting routine boosters may not be essential6. A longitudinal study tracking individuals over 22 years demonstrated an anamnestic response upon booster administration, reinforcing the idea that initial vaccination confers lasting immunity through cellular mechanisms rather than detectable antibody titers alone7,8. These findings align with CDC recommendations, which do not advocate routine boosters for healthy adults7.

Conversely, other research highlights a decline in seroprotection among vaccinated HCWs, with one Indian study reporting that 30% had anti-HBs levels below 10 IU/mL within five years. This study advocated for periodic monitoring and targeted booster administration to mitigate occupational risk4. Furthermore, it demonstrated that post-booster antibody titers increased significantly, with a mean of 1359.2 IU/mL compared to 419.6 IU/mL in unboosted individuals (P<0.001), suggesting that boosters could substantially enhance protection where immunity has waned4.