Waec Model Questions Vol1 2022 Biology Question 15

Practice objective / multiple choice question 15 from the 2022 Waec Model Questions Vol1 Biology examination.

Waec Model Questions Vol1 2022 Biology Objective / Multiple Choice Hard Difficulty
Question 15 WAEC_MODEL_QUESTIONS_VOL1 • 2022 • BIOLOGY • objective

In a closed community of 10 000 people an infectious disease has a basic reproduction number $R_{0}=2.5$. A vaccination programme immunises 60 % of the population with a vaccine that is 90 % effective. Assuming homogeneous mixing, (i) calculate the effective reproduction number $R_{e}$ after vaccination and state whether herd immunity is achieved, and (ii) determine the minimum vaccination coverage (with the same vaccine efficacy) required to achieve herd immunity.

Answer Options

A. Re = 1.30 (no herd immunity); minimum coverage ≈ 55 %
B. Re = 0.75 (herd immunity); minimum coverage ≈ 80 %
C. Re = 0.90 (herd immunity); minimum coverage ≈ 60 %
Correct Answer D. Re = 1.15 (no herd immunity); minimum coverage ≈ 66.7 %
Correct Answer
D
Correct Option:
Re = 1.15 (no herd immunity); minimum coverage ≈ 66.7 %

About This Question

This is Waec Model Questions Vol1 2022 Biology Question 15. It is one of the objective questions from the 2022 Waec Model Questions Vol1 Biology examination.

Difficulty level: Hard .

View More Waec Model Questions Vol1 2022 Biology Questions More Waec Model Questions Vol1 Practice Questions Back to Questions

Master the Exam!

You've seen a preview, but there are thousands more questions plus AI tutor to break down complex solutions.

Unlock Full Access Available for Android & Windows
Chat with Support