Factors Associated with Vaccination Completeness and Knowledge About Hepatitis B Among Undergraduate Nursing Students in Northeastern Brazil: A Cross-Sectional Study

Hepatitis B remains an important occupational risk for undergraduate nursing students, particularly due to potential exposure, making vaccination and infection knowledge essential for protection throughout their professional careers. Objective: This study aimed to analyze the factors associated with vaccination completeness and knowledge about hepatitis B among undergraduate nursing students in Northeastern Brazil. Methods: An analytical cross-sectional study was conducted with undergraduate nursing students from three campuses of a public university in Northeastern Brazil. Data were collected between October and December 2025 using validated instruments that assessed sociodemographic and academic characteristics, knowledge, and vaccination status through analysis of vaccination cards. Associations were assessed using multivariable binomial logistic regression, and results are shown as adjusted odds ratios and 95% confidence intervals. Results: Vaccination completeness (minimum of 3 doses of HepB vaccine) was observed in 74.3% of the undergraduate nursing students, while 57.9% demonstrated adequate knowledge about hepatitis B (minimum of 75% of assessment questions properly answered). The variables associated with lower odds of vaccination completeness were a family income lower than two minimum wages, not having taken the infectious diseases course, absence of training on hepatitis B, not having undergone rapid test for sexually transmitted diseases, and reported current use of illicit drugs. Regarding inadequate knowledge about hepatitis B, students who had not taken the course related to infectious diseases and those who had not undergone rapid tests for HIV, syphilis, and hepatitis B were more likely to have inadequate knowledge. In contrast, hepatitis B training and previous rapid testing were associated with lower likelihood of inadequate knowledge. Conclusions: A substantial proportion of nursing students was incompletely vaccinated, while most demonstrated a good level of knowledge about hepatitis B. The findings reinforce the need to strengthen immunization initiatives from the beginning of undergraduate education, particularly by improving access to vaccination and providing training on hepatitis B.