Research evidence suggests that communication is a powerful tool for influencing public opinion and attitudes toward various health-related issues, such as vaccine reluctance, provided it is well-designed and thoughtfully conducted. In particular, social marketing techniques that alter the target audience’s behaviors for the public good can substantially improve vaccine uptake if adopted as a communication strategy in immunization programs to counter public hesitancy. This study presents evidence from the Korean government’s current coronavirus disease 2019 (COVID-19) vaccination campaign, which successfully applied a social marketing approach. By the end of August 2022, South Korea had achieved high vaccine coverage, with 94.8% of the population (12+) receiving a second dose, 71.3% a third dose, and a fourth dose drive currently underway. There are five crucial factors to consider when preparing official communication for an immunization program: (i) a high degree of proactiveness, (ii) credibility, (iii) fighting misinformation, (iv) emphasizing social norms and prosocial behavior, and (v) coherence. Although using social marketing strategies may not be successful in all circumstances, the lessons learned and current implementation in Korea suggest their efficacy in fostering vaccine acceptance. This study offers valuable insights for government agencies and global public health practitioners to develop effective targeted campaign strategies that enhance the target population’s vaccination intention.