Dec 3, 2025 · Virus, infectious agent of small size and simple composition that can multiply only in living cells of animals, plants, or bacteria. Viruses possess unique infective properties and thus …

Viruses are tiny particles that cause disease in people, other animals, and plants. Different viruses cause the common cold, influenza (flu), chicken pox, measles, AIDS, and many other diseases.

3 days ago · Influenza is caused by viruses in the family Orthomyxoviridae. Learn more about the classification of influenza viruses, influenza outbreaks, and influenza symptoms and treatment.

Oct 31, 2025 · Phages are classified in a number of virus families; some examples include Inoviridae, Microviridae, Rudiviridae, and Tectiviridae. Like all viruses, phages are simple …

Oct 18, 2025 · A virus consists of a set of instructions that attaches itself to other computer programs, usually in the computer’s operating system, and becomes part of them.

Nov 21, 2025 · Retrovirus, any of a group of viruses that belong to the family Retroviridae and that characteristically carry their genetic blueprint in the form of ribonucleic acid (RNA).

Nov 14, 2025 · In some people the virus gets no farther, causing only a vague flulike illness to develop. The most common early symptoms of polio are mild headache, fever, sore throat, …

The protein capsid provides the second major criterion for the classification of viruses. The capsid surrounds the virus and is composed of a finite number of protein subunits known as …

Nov 8, 2025 · In late 2019 a virus closely related to SARS coronavirus emerged in Wuhan, China. The virus, later named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), …

Nov 23, 2025 · HIV is a lentivirus (literally meaning “slow virus”; a member of the retrovirus family) that slowly attacks and destroys the immune system, the body’s defense against infection.