Final answer:
Interferon-alpha (IFN-α) is secreted by virally infected cells to alert nearby uninfected cells of a viral infection. It stimulates uninfected cells to produce compounds that interfere with viral replication and activates other cells in the immune response.
Step-by-step explanation:
Interferon-alpha (IFN-α) is secreted by virally infected cells. It is a type of early-acting cytokine released by infected cells to alert nearby uninfected cells of a viral infection. Interferons stimulate uninfected cells to produce compounds that interfere with viral replication and also activate macrophages and other cells in the immune response.