Suppose we identify a 58-year-old child with influenza in the village but are uncertain whether the child

Question:

Suppose we identify a 5€“8-year-old child with influenza in the village but are uncertain whether the child was vaccinated. If we make the same assumptions as in Problems 3.29€“3.30, then what is the probability that the child was vaccinated?

Suppose that 80% of 3€“4-year-old children and 70% of 5€“8-year-old children in a village are vaccinated with QIV vaccine. Also assume that children who are not vaccinated have twice the incidence of influenza as the control group in Table 3.7.

Table 3.7 Attack rate for influenza by age and treatment group

OIV group Control group age 3.78% 5.69% 5.15% 3-4 5-8 1.70%