A nurse offers homeless clients yearly tuberculosis (TB) screening. Which of the following levels of prevention is being used?

Choice A reason: Acquired immunity includes any immunity gained post-birth, like via vaccines or infection. It’s broad, encompassing this scenario, but less specific than active immunity, which details the body’s direct response to measles antigens, producing antibodies and memory cells for long-term protection explicitly.

Choice B reason: Active immunity occurs when vaccinations trigger the immune system to produce antibodies against measles virus antigens. This process, involving B and T cells, builds memory, offering lasting protection, distinguishing it from passive or natural methods by its active, self-generated response biologically and effectively.

Choice C reason: Herd immunity arises when most of a population is immune, reducing measles spread indirectly. Vaccination contributes, but this describes a community effect, not the individual immunity type gained directly from the shot, which is the question’s specific focus here distinctly.

Choice D reason: Natural immunity follows actual measles infection, not vaccination. It involves the body fighting the live virus, unlike the controlled antigen exposure from shots, which mimics this process artificially, making it less applicable to the immunity type described in this scenario fully.

Choice A reason: Designing a game teaches healthy choices, a primary prevention. Weighing identifies obesity, per nursing standards. This errors as it’s not secondary. It’s universally distinct, focusing on prevention, not detection.

Choice B reason: Dieting after weight gain is tertiary, managing obesity. Weighing screens early, per public health. This misaligns with secondary prevention. It’s universally distinct, treatment-based.

Choice C reason: Exercise presentations are primary, preventing obesity onset. Weighing detects it, per nursing standards. This errors as it’s not secondary. It’s universally distinct, preemptive not screening.

Choice D reason: Weighing students screens for obesity, a secondary prevention strategy. This aligns with public health standards. It’s universally applied, distinctly identifying at-risk children effectively.