Why did some physicians and religious groups oppose variolation?

Opposition to variolation stemmed primarily from the significant medical risks associated with the procedure. Although it was intended to induce a milder form of smallpox, the method involved infecting healthy individuals with actual smallpox material. Consequently, recipients could still develop a full-blown, severe case of the disease and potentially spread the infection to others, making the practice dangerous and unpredictable.1

Because of these inherent risks, many physicians remained skeptical or opposed to the practice. Additionally, some religious groups objected to variolation, viewing the deliberate infection of a healthy person as an interference with divine will or a violation of moral principles regarding the preservation of health. These concerns persisted until the development of cowpox inoculation by Edward Jenner, which offered a safer alternative and eventually led to the abandonment and legal prohibition of variolation.1