system
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.
user
Herd immunity is not useful in -
assistant
The correct answer is  Herd immunity has been achieved in diphtheria and poliomyelitis Small pox-herd immunity has not played a crucial role in its eradication. Tetanus- herd immunity doesn't protect the individuals ( refer pgno:103 park 23 rd edition)