Herd Immunity Through Vaccination

Steps:

• Identify the goal: Control disease spread by reducing transmission in the population.
• Recall vaccination effect: Vaccines induce immunity, preventing infection in recipients.
• Link to population control: High vaccination rates limit susceptible hosts, breaking transmission chains.
• Evaluate options: Select the one explaining reduced catching and spreading by vaccinated individuals.

Why B is correct:

• Vaccinations confer active immunity, preventing vaccinated people from catching and transmitting the disease, which reduces overall spread per herd immunity principles.

Why the others are wrong:

• A: Meeting patterns are unrelated to vaccination's biological protection against infection.
• C: Unvaccinated remain susceptible and can catch the disease, enabling spread.
• D: Vaccinations provide artificial active immunity, not natural (from prior infection).

Final answer: B