The MMR vaccine protects individuals from the diseases commonly known as measles, mumps, and rubella. This vaccination is not recommended for pregnant individuals or immunocompromised individuals. Knowing this, the MMR vaccine must be:

• A. An inactivated vaccine.
• B. An attenuated vaccine.
• C. A toxoid vaccine.
• D. Antibodies from patients previously infected by these diseases.

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the types of vaccines and their characteristics. Inactivated vaccines contain killed pathogens, attenuated vaccines contain weakened live pathogens, toxoid vaccines contain inactivated toxins, and antibody-based treatments provide passive immunity.
2. Step 2: Recognize that the MMR vaccine protects against measles, mumps, and rubella, which are viral diseases requiring a strong immune response for effective protection.
3. Step 3: Note that the MMR vaccine is not recommended for pregnant or immunocompromised individuals because it contains live, weakened viruses that could potentially cause disease in these vulnerable groups.
4. Step 4: From this, deduce that the MMR vaccine must be an attenuated vaccine, as inactivated or toxoid vaccines do not carry the same risk and antibody treatments are not vaccines but passive immunity.
5. Step 5: Conclude that the MMR vaccine is an attenuated vaccine, which uses live but weakened viruses to stimulate a strong and lasting immune response without causing the disease in healthy individuals.