The Possible Protective Effect of Hepatitis B Vaccine against Lymphomas: A Systematic Review

Background: In the last few years, the possible etiological role of the Hepatitis B virus (HBV) in the outbreak of extrahepatic pathologies has been studied, including lymphomas. The World Health Organization (WHO) estimates that around 257 million people live with chronic HBV infection, and to date, the vaccine is the most effective means of prevention. Objective: The aim of this review was to evaluate whether the vaccination against Hepatitis B can lead to a reduction in lymphoma cases and has a protective role. Methods: A literature search was conducted in April 2020 using the databases Scopus, PubMed, and ISI Web of Science. Search terms included: "Hepatitis B vaccination AND lymphoma." All articles evaluating the association between Hepatitis B vaccination and the prevention of lymphoma were selected. No limits were applied. Results: Eight studies were eligible to be included in the review. Data showed that association between lymphoma and HBV infection is not the same for all types of lymphomas, but it appears to be more significant for Non-Hodgkin Lymphoma (NHL). The results from all the considered articles were not unitary. This is because studies were conducted in different countries with different endemicity of Hepatitis B, different vaccination coverage, treatment of chronic Hepatitis, and prevention of its complications, as well as the availability of data for researchers. No statistically significant association was found between HBV vaccination and the development of lymphomas. Conclusion: Although the literature is still largely lacking regarding the protective effect of anti-HBV vaccination on lymphoma subtypes, the association between HBV infection and lymphoma has been confirmed in several studies. Vaccination programs eliminate the risk of HBV infection and prevent liver disease but can also indirectly reduce the risk of lymphomas.