When one individual becomes immunized by receiving a series of vaccine injections according to schedule, the resulting protection extends to that individual's nearby contacts. This concept is

When one individual becomes immunized by receiving a series of vaccine injections according to schedule, the resulting protection extends to that individual's nearby contacts. This concept is

• A. Immunologic memory.
• B. Neighborhood immunity.
• C. Herd immunity.
• D. Contagious immunity.

Answer: (C)

Herd immunity is the idea that when a large portion of a community is immune to a disease, the spread of that disease is slowed or stopped, providing protection to people who are not immune. When many individuals are vaccinated, transmission chains are interrupted, so even unvaccinated or vulnerable people are less likely to encounter someone who can spread the infection. This indirect protection to nearby contacts is the hallmark of herd immunity. Immunologic memory, while crucial for how vaccines work at the individual level (the immune system recalls and responds more effectively upon exposure), does not by itself explain protection extending to others. Neighborhood immunity and contagious immunity aren’t standard terms for this phenomenon; the established term is herd immunity.

Herd immunity is the idea that when a large portion of a community is immune to a disease, the spread of that disease is slowed or stopped, providing protection to people who are not immune. When many individuals are vaccinated, transmission chains are interrupted, so even unvaccinated or vulnerable people are less likely to encounter someone who can spread the infection. This indirect protection to nearby contacts is the hallmark of herd immunity.

Immunologic memory, while crucial for how vaccines work at the individual level (the immune system recalls and responds more effectively upon exposure), does not by itself explain protection extending to others. Neighborhood immunity and contagious immunity aren’t standard terms for this phenomenon; the established term is herd immunity.