Background: Public health officers (PHOs) are the frontline health workforce against the Coronavirus disease 2019 (COVID-19) and therefore need high immunity for protection. The application of the capability, opportunity, motivation, and behavior (COM-B) model aimed to 1) explore the level of COM-B for prevention and control of COVID-19, and 2) analyze the association between factors and behaviors for prevention and control of COVID-19 among PHOs at primary care units (PCUs) of seven provinces in southern Thailand.

Methods: The study design performed an analytical cross-sectional study using information from primary care units from July to September 2021. Data collection used multi-stage sampling techniques to construct the online questionnaire based on the relationship of the COM-B model. Data analysis used descriptive statistics, and Chi-squared and Fisher’s exact tests to find out the association among factors.

Results: The overall COM-B scores of the 203 PHOs were high, but the motivation was low. Almost all characteristics were associated with behavior. Work experience was significantly associated with capability, opportunity, and behavior (P < 0.05). The relationships between capability and behavior, and opportunity and motivation were statistically significant (P < 0.05 and P < 0.001 respectively).

Conclusions: This is the first report applying the COM-B model to explore behavior changes relating to the COVID-19 vaccination among PHOs at PCUs. The association between factors and individual behavior of health providers can be applied to design interventions for promoting effective preventive and controlling behavior after the COVID-19 vaccination.