Final answer:
For an immunocompromised 12-month-old infant, live vaccines such as varicella and MMR (Measles, Mumps, Rubella) are contraindicated, while Hepatitis B and DTP (Diphtheria, Tetanus, Pertussis) are not.
Step-by-step explanation:
For a 12-month-old immunocompromised infant, certain live vaccines are contraindicated due to the potential risk of causing disease due to the infant's weakened immune system. Among the vaccines listed, varicella and MMR (Measles, Mumps, Rubella) are live vaccines. Immunocompromised individuals should not receive these vaccines without seeking medical advice, as they can potentially cause harm. On the other hand, the Hepatitis B and DTP (Diphtheria, Tetanus, Pertussis) vaccines are not live vaccines. Hepatitis B is typically the first vaccination given at birth to protect against serious liver disease, and the DTP vaccine is a combination vaccine providing protection against diphtheria, tetanus, and pertussis. Due to the nature of the immune-compromising condition, the varicella and MMR vaccines are contraindicated.