library(tidyverse)
vactrialFrame <- tibble(
  Infection = factor(c(rep("Yes", 162), rep("No", 18163), rep("Yes", 8), rep("No", 18190))),
  Treatment = factor(c(rep("Placebo", 18325), rep("Vaccine", 18198)))
)


vactrialContingency <- table(vactrialFrame)
vactrialContingency

fisher.test(vactrialContingency)
chisq.test(vactrialContingency)
prop.test(c(162,8), c(18325,18198))