Some viruses, especially animal viruses, have an envelope surrounding their nucleocapsid. This envelope may have viral proteins embedded in it. Why are the viral proteins more readily recognized and targeted by the immune system than the envelope?

The viral proteins are more readily recognized by the immune system, as they are more distinct from the materials normally found in and on the cells.

Explanation:

The immune system mainly functions to identify the components that are not normally found in the organism and hence identify it as a foreign body and generate an immune reaction against it to eliminate it. Enveloped viruses are often coated with animal cell membranes as they leave the cell and thus, the envelope is mainly made up of the components that are similar to that of the organism's cell membrane and hence the immune system fails to identify it as a foreign entity. As a result of this, the viral proteins that are quite distinct from the materials found inside or outside the cell of the host organisms are targeted by the immune system.