Interferons and Cytokine Barriers — NEET Biology

Interferons are antiviral proteins secreted by virus-infected cells that protect neighboring uninfected cells from viral infection. This is a key part of innate immunity and acts as an early defense mechanism. Students often confuse interferons with antibodies or mistake them as directly killing viruses themselves, when they actually prevent viral entry or replication in nearby cells. The critical point to remember: interferons are a non-specific, immediate response that protects uninfected cells before adaptive immunity kicks in. NTA tests this concept to check if students understand the layers of viral defense—especially the cytokine barrier as part of the first line of defense in the immune system.