BackgroundDespite the proven therapeutic potential of bivalent vaccine primer doses against COVID-19, acceptance of vaccine booster doses (VBD) varies among various subgroups of the global population. This study investigated the acceptance of COVID-19 VBD among trainees and students of health professions in Bangladesh and compared the potential factors influencing their VBD decisions. MethodsThe questionnaire was deployed in an online-enabled layout and conveniently sent to encounters between 10th June 2023 and 10th September 2023. Data from 501 trainees and 501 students were compared (response rate 80.8% vs.78.3%) to explore the study objectives. ResultsThe pooled COVID-19 VBD acceptance rates were 90.2% (95% Confidence Interval [CI]:87.6─92.8) vs. 93.2% (95% [CI]: 91.2─95.2) between trainees and students. The binary logistic analysis revealed that out of twelve factors “equal safety” (Adjusted odds ratio [aOR]: 4.476 vs. 6.459), “efficacy” ([aOR]:3.673 vs. 2.913), “repeated immunity” ([aOR]: 1.729 vs. 2.247), and “self-priority” ([aOR]:3.108 vs. 4.645) had a significant positive association (p<0.01 and p<0.05) with VBD acceptance in both groups. There were varied effects on several predictors. Among trainee professionals, "communication" and "booster mandate" were associated significantly ([aOR]:1.534 and 1.748, respectively; p<0.05) with VBD acceptance, whereas "information source" and "culture" were associated ([aOR]:3.692 and 3.151, respectively; p<0.05) significantly with VBD acceptance in the student cohort. ConclusionsThere was a satisfactory acceptance level of COVID-19 VBD among healthcare participants, and several multidimensional factors influenced their VBD decisions in different ways. For enhancing public booster immunization decisions against COVID-19, individual health expectations must be linked to wider societal influences.