Viral-infected human cells often send out special proteins that serve as an early warning system to uninfected cells. In response, the uninfected cells develop antiviral proteins that protect them. The early warning proteins sent out by viral-infected cells are

Interferons

Explanation:

Interferons can be defined as the cells that is already being virus affected and they release some chemicals out of it in order to prepare the cells or to enhance the cells for anti-viral response.

The cells a group of signaling proteins which is being released by the host cells in response to the presence of virus in the body.

Chemically they are cytokine molecules which is used as a defense mechanism to protect the other cells of the body from being infected.

Certain response like fever, muscle pain are caused by the interferon.

it would be a lot of diff ones. hope this ! < 3 : )