In theory, it is possible to increase the infectivity or lethality of certain pathogens in the laboratory through gene editing and other biotechnological means. However, such experiments are extremely dangerous and involve huge ethical and safety risks. The vast majority of countries and scientific research institutions have strict legal and ethical guidelines to restrict or prohibit such experiments to prevent potential abuse and accidental epidemic outbreaks. Enhancing the infectivity or lethality of pathogens may lead to unexpected consequences and pose a serious threat to public health. Therefore, the international scientific community generally opposes such research unless it is conducted in a very controlled environment and the purpose is to increase understanding and develop effective countermeasures. The laws of many countries and international conventions (such as the Biological Weapons Convention) have clear prohibitions on the development of biological weapons. Therefore, great caution must be exercised when synthesizing more infectious and lethal pathogens to ensure that all research is conducted under a highly regulated and ethical review framework to prevent possible catastrophic consequences.