Viruses are considered by some biologists to be a life form, because they carry genetic material, reproduce, and evolve through natural selection, although they lack some key characteristics, such …

5 days ago · Last year’s outbreaks were the largest in a decade, fueled by an emerging variant of the highly contagious, hard-to-kill virus. What will this year look like?

Mar 29, 2023 · A virus is a small piece of genetic information in a “carrying case” — a protective coating called a capsid. Viruses aren’t made up of cells, so they don’t have all the equipment that cells do to …

3 days ago · 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 often cause …

The mechanism by which a virus is transmitted depends on several things, including which organisms the virus is able to infect, which types of cells in those organisms the virus can infect, and how the …

3 days ago · A virus is an infectious microbe consisting of a segment of nucleic acid (either DNA or RNA) surrounded by a protein coat. A virus cannot replicate alone; instead, it must infect cells and …

Apr 12, 2025 · When a virus enters the body, the innate immune system reacts first. This non-specific defense includes barriers like skin, as well as cells that engulf and destroy invaders. If the virus gets …

Oct 19, 2023 · Viruses are microscopic biological agents that invade living hosts and infect their bodies by reproducing within their cell tissue. Viruses are tiny infectious agents that rely on living cells to …

14 hours ago · Seasonal flu and norovirus are circulating right now. But which illness do you have? Doctors share what to look for when comparing norovirus vs. flu symptoms.

Viruses are microscopic entities that exist on the border of what is considered living, impacting all forms of life from bacteria to humans. These tiny invaders are responsible for a wide array of diseases, …