Around the world, COVID-19 is continuing to threaten the health of millions, interrupt daily life, and throttle business activity. In Thailand, the latest wave of infections has been more intense than any since the beginning of the pandemic, and many businesses have been forced to close down once again. There are reasons for hope though—chief among them the increasing pace of vaccinations. Not only are the vaccines effective at preventing serious health issues, they are helping keep both employees and customers safe in business settings so that commerce, trade, and tourism can resume once again. Many in Thailand have already been vaccinated, and struggling employers are looking ahead to safely resuming full business activities, from reopening offices for employees who have been working from home, to welcoming customers and clients back to an environment that minimizes the risk of COVID-19 exposure. In anticipation of such a return to business at full capacity, many Thai employers are taking note of companies and organizations overseas boosting COVID-19 safety in workplaces by mandating vaccines and other measures, and asking whether such mandates could be imposed here in Thailand. The main legal concept to consider here is the provision in the Labor Protection Act B.E. 2541 (1998), which authorizes employers to issue “lawful and just” orders to employees. For an order to be “lawful and just,” it must be proportionate to the circumstance. In the current context of the COVID-19 pandemic, employers can refer to the Communicable Diseases Act B.E. 2558 (2015), as well as other local regulations, to provide grounds when asserting that their risk-mitigation orders are proportionate, lawful, and just. It is doubtful that a Thai court would rule that the circumstances we find ourselves in now would justify an employer requiring employees to be vaccinated, but this legal standard can