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Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
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Causes of antigenic drift in influenza viral infections:
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The correct answer is  Ans. is 'a' i.e., Small mutations in neuraminidase and hemagglutinin Antigenic drift: The gradual, sequential, regular antigenic change in influenza virus is known as antigenic drift. This occurs due to minor antigenic changes due to point mutations in the HA or NA occurring at frequent intervals. This is caused even by a single mutation affecting HA glycoprotein. The antigenic drift is characterized by changes in certain epitopes in the HA, while others are being conserved.