👉 Infection, particularly viral infections like influenza or COVID-19, occurs when a pathogen enters a host and begins to replicate within cells. The process starts with the pathogen attaching to specific receptors on the surface of host cells, often through proteins on its outer layer. Once attached, the pathogen can inject its genetic material into the cell, hijacking the cell’s machinery to produce more copies of itself. This rapid replication leads to the infection, causing cellular damage and triggering the body's immune response. The infection progresses as more cells become infected, leading to symptoms such as fever, cough, and fatigue, depending on the pathogen. Understanding the mechanisms of infection is crucial for developing treatments and preventive measures like vaccines and antiviral drugs.
