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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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Threshold level of herd immunity of Peussis is -
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The correct answer is  Park&;s texbook of Preventive and Social Medicine 23rd edition Page no: 165 The control of peussis by immunization is still an unsolved problem Even if the level of immunization reaches 100 per cent, it is possible that the disease would not be entirely eliminated because whooping cough vaccines have never been claimed to be more than 90 per cent effective.