Igcse Model Questions Vol1 2022 Biology Question 12

Practice objective / multiple choice question 12 from the 2022 Igcse Model Questions Vol1 Biology examination.

Igcse Model Questions Vol1 2022 Biology Objective / Multiple Choice Hard Difficulty
Question 12 IGCSE_MODEL_QUESTIONS_VOL1 • 2022 • BIOLOGY • objective

A contagious disease has a basic reproduction number of \(R_0 = 3\). A vaccine available for this disease is 70\% effective.\n(a) Calculate the minimum proportion of the population that must be vaccinated to achieve herd immunity.\n(b) If only 85\% of the population is vaccinated, can an outbreak still occur? Justify your answer.

Answer Options

Correct Answer A. At least about 95 % of the population must be vaccinated; with 85 % coverage the disease could still spread.
B. At least about 70 % of the population must be vaccinated; with 85 % coverage the disease could still spread.
C. At least about 95 % of the population must be vaccinated; with 85 % coverage the disease would not spread.
D. At least about 85 % of the population must be vaccinated; with 85 % coverage the disease would be eliminated.
Correct Answer
A
Correct Option:
At least about 95 % of the population must be vaccinated; with 85 % coverage the disease could still spread.

About This Question

This is Igcse Model Questions Vol1 2022 Biology Question 12. It is one of the objective questions from the 2022 Igcse Model Questions Vol1 Biology examination.

Difficulty level: Hard .

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