Which of the following individuals are contraindicated from receiving the MMR vaccine?

The MMR vaccine, which protects against measles, mumps, and rubella, is a live attenuated vaccine. This means it contains weakened forms of the viruses that can stimulate an immune response without causing disease in healthy individuals. However, certain populations should avoid receiving live vaccines due to the risk of infections that could arise from the live attenuated virus.

In this scenario, pregnant women are typically advised to avoid live vaccines, including the MMR vaccine. During pregnancy, especially in the third trimester, a woman's immune system is altered, and this can lead to a higher risk of experiencing complications. The concern also extends to potential risks to the fetus, as there may be effects on fetal development from the live attenuated viruses present in the vaccine. For these reasons, the 23-year-old in her third trimester is contraindicated from receiving the MMR vaccine.

The other individuals listed do not have the same level of contraindications associated with the MMR vaccine. It is important to recognize their specific health conditions; for instance, the individual with a low platelet count may require evaluation based on the severity of the condition, but this does not universally contraindicate vaccination. Similarly, age or chronic conditions like COPD or asplenia don't outright prevent individuals