Primary Cancer Prevention Through Vaccination: Advances, Challenges, and Global Perspectives.

Oncogenic viral and bacterial infections constitute a significant portion of the global cancer burden, accounting for up to 15% of cases, particularly in low- and middle-income countries. Prophylactic vaccination thus appears to be the most effective tool for preventing these preventable cancers, especially those linked to human papillomavirus (HPV) and hepatitis B virus (HBV). This narrative review synthesizes recent data concerning the impact, advances, limitations, and prospects of available and developing cancer vaccines. Research shows that HPV vaccination significantly reduces the incidence of vaccine-specific infections, precancerous lesions (CIN2+), and, in the longer term, invasive cancers, with an enhanced effect when vaccination coverage is high and administration is early. Similarly, the universal introduction of the HBV vaccine has led to a remarkable decrease in chronic infections and hepatocellular carcinoma, as evidenced by the successes observed in Taiwan and The Gambia. Despite these advances, challenges remain, including limited access, costs, logistics, sociocultural acceptability, and insufficient vaccination coverage, particularly for the birth dose of HBV and in resource-limited countries. Furthermore, several prophylactic vaccines against oncogenic agents such as EBV,