Living Environment Regents Practice Test

Why might a mother not get sick from measles after being close to her infected child?

1. The mother is planning to get vaccinated soon.

2. The mother had been vaccinated against measles.

3. The mother has never been tested for measles immunity.

4. The mother was not in the same room as the child.

The correct answer is: The mother had been vaccinated against measles.

The correct answer highlights that the mother had been vaccinated against measles, which provides her with immunity to the virus. Vaccination stimulates the immune system to produce antibodies that can recognize and fight off the measles virus if the individual is exposed. Because measles is highly contagious, being close to an infected person increases the likelihood of contracting the disease. However, if the mother has been vaccinated, her immune system is prepared to combat the virus, protecting her from falling ill despite the exposure. This immunity can also stem from having had measles previously, as recovering from the infection typically confers lifelong immunity. In this context, the mother’s vaccination status plays a critical role in her health, even in close proximity to an infected individual. The other options do not provide a valid reason for her not getting sick; for example, planning to get vaccinated soon would not confer immediate protection, and being untested does not imply immunity. Similarly, not being present in the same room implies separation, which would not apply if they were indeed close together.