Question

A small public school in northern California experienced an outbreak of pertussis (whooping cough). Pertussis was observed to develop in 31 of 96 unvaccinated children, 26 of 489 vaccinated children, and 14 of 67 children with unknown vaccination status. Are the unvaccinated students and those of unknown vaccination status at higher risk of pertussis? Calculate the appropriate measure of excess risk for the unvaccinated students versus the vaccinated students and for those with unknown vaccination status versus the vaccinated students (i.e., the vaccinated students are the unexposed). Interpret your results in plain language.

Answer 1

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