CD4 <- as.factor(c(0,1,0,1,2,1,2,2)) # level at birth
CD8 <- as.factor(c(2,2,0,1,2,0,0,1)) # level at birth
HIV <- c(1,2,4,4,1,2,0,0)      # HIV positive at 6 months
m <- c(1,2,7,12,3,7,2,13) # number of infants

cbind(CD4,CD8,HIV,m)

SF <- cbind(HIV,m-HIV)
SF

glm.obj <- glm(SF~CD4,binomial)
summary(glm.obj)
dropterm(glm.obj,test="Chisq")

glm.obj <- glm(SF~CD8,binomial)
summary(glm.obj)
dropterm(glm.obj,test="Chisq")

glm.obj <- glm(SF~CD4+CD8,binomial)
summary(glm.obj)
dropterm(glm.obj,test="Chisq")

p.model <- predict(glm.obj,type="response")
p.emp <- HIV/m
plot(p.emp,p.model,pch=16,col=2)
abline(a=0,b=1)