Viral envelope

A viral envelope is a protective outer layer surrounding some viruses, derived from the host cell's membrane during viral replication. It consists mainly of lipids and proteins that the virus acquires from the host cell, which helps it enter new cells more easily by merging with their membranes. This envelope also contains specific proteins essential for attaching to and infecting host cells. Not all viruses have envelopes; those that do often tend to be more sensitive to environmental conditions but can efficiently infect their target cells thanks to this specialized outer layer.