<prompt> Cholera prophylaxis is by -Doxycycline 300mg ODCephalosporinStreptomycinCotrimoxazole  <response>: A single oral dose of doxycycline 300mg for adults and 6mgkg for children under 15 years has proved to be effective for chemoprophylaxis of cholera. Ref: PARK;S TEXTBOOK OF PREVENTIVE AND SOCIAL MEDICINE 23rd edition , Page 233 