Efforts to establish a coordinated international response to diseases that affect more than one country go back to the mid-19th century. Nowadays World Health Organization is the central point where the interests of 194 member states to preserve the health of their populations are convened, coordinated, and addressed. The critical concept that initiates an international reaction is a public health emergency of international concern, as exemplified by the COVID-19 pandemic. As of October 2022, it had claimed an estimated 20 million lives worldwide. Both in Serbia and elsewhere, the death toll greatly depended on the applied prevention and control measures, which included vaccination. Experiences gained so far point to preferable strategies that should be employed when humanity is confronted with the next similar challenge.