Understanding the Dual Nature of Immunity

The late 1800s marked a significant shift in the understanding of immunity, particularly with the rise of allergic reactions and vaccine responses. Initially, conditions resembling anaphylaxis, such as those caused by insect stings and snake bites, were not recognized as allergies due to the absence of appropriate terminology and scientific understanding. During the Industrial Revolution, a notable increase in cases of persistent colds and asthma began to surface, leading to the concept of hay fever. Pioneering clinician Clemens von Parquet observed adverse reactions, including fevers, in children after receiving vaccines, challenging the prevailing belief that the immune system only functions to protect. He proposed that the immune system might possess a 'dark side,' capable of causing harm rather than solely providing defense. This transformative insight laid the groundwork for modern immunology, emphasizing the complexity and dual nature of immune responses.