The substance produced by a cell in viral infection that can protect other cells from further infection is:

The substance produced by a cell in viral infection that can protect other cells from further infection is interferon. Interferon is a group of proteins released by the host cell in the presence of virus. In classic cases the viral infected cell releases interferon which heightens the antiviral response of the nearby cells.

Serotonin: It is a Monoamine Neurotransmitter which is involved in the state of being happy.

Colostrum: It is the first milk produced by the mammary glands after childbirth. It consists of antibodies that help in boosting the immune system of the newborn.

Histamine: It is a nitrogenous compound involved in immune responses. Mainly there are H1 and H2 forms of histamine.