Comment by ggrothendieck

Furthermore a test just twice as large would be sufficient to determine significance at the 1% level even with a two sided test if the same death rate continued to hold.

  ivm <- c(3, 247-3)
  con <- c(10, 249-10)
  m <- rbind(ivm, con)
  fisher.test(2*m)$p.value  # 2* so that it is twice as large
  ## [1] 0.008490957