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What is The protection against small pox by previous infection with cowpox represents: and explain in detail?
Ans. is 'a' i.e., Antigenic cross-reactivity(Ref: Ananthanarayan, 7th/e, p. 81, 82)* Antigenic cross reactivity - Sometimes single antigen stimulates production of variety of antibodies that more or less resemble the correct fit for the antigen. Each of these antibodies may attack different antigens that more or less resemble one another.