👉 Infections are a fundamental aspect of human biology, representing the invasion and proliferation of microorganisms—such as bacteria, viruses, fungi, and parasites—within a host organism. These pathogens can enter the body through various routes, including inhalation, ingestion, or direct contact, and they often exploit the host's own cellular machinery to replicate and spread. The immune system responds to infections by mounting a complex defense mechanism, involving both innate and adaptive responses. The innate response provides immediate, non-specific protection, while the adaptive response generates tailored defenses, such as antibodies and memory cells, to combat specific pathogens. Understanding infections is crucial for developing effective treatments and preventive measures, including vaccines, antibiotics, and hygiene practices, which aim to disrupt the infection cycle and protect public health.
