openintro (version 2.4.0)

malaria: Malaria Vaccine Trial

Description

Volunteer patients were randomized into one of two experiment groups where they would receive an experimental vaccine or a placebo. They were subsequently exposed to a drug-sensitive strain of malaria and observed to see whether they came down with an infection.

Usage

malaria

Format

A data frame with 20 observations on the following 2 variables.

treatment

Whether a person was given the experimental vaccine or a placebo.

outcome

Whether the person got an infection or no infection.

Details

In this study, volunteer patients were randomized into one of two experiment groups: 14 patients received an experimental vaccine or 6 patients received a placebo vaccine. Nineteen weeks later, all 20 patients were exposed to a drug-sensitive malaria virus strain; the motivation of using a drug-sensitive strain of virus here is for ethical considerations, allowing any infections to be treated effectively.

Examples

library(dplyr)

# Calculate conditional probabilities of infection after vaccine/placebo
malaria %>%
  count(treatment, outcome) %>%
  group_by(treatment) %>%
  mutate(prop = n / sum(n))

# Fisher's exact text
fisher.test(table(malaria))