Antibiotics are medicines used to treat bacterial infections. Explain why antibiotics are not prescribed for patients suffering from a viral infection.

Antibiotics work by targeting structures or processes that are unique to bacteria, such as the bacterial cell wall or bacterial ribosomes. Viruses do not have these structures; they replicate only inside host cells by using the cell’s own machinery. Because antibiotics cannot penetrate host cells effectively, they cannot reach or affect the virus. Moreover, using antibiotics when a virus is present would give no benefit and would contribute to the development of antibiotic‑resistant bacteria such as MRSA, so they are avoided.