Manipulating legend with ggplot

Question

I'm trying to change the legend in my figure and I've never had this much trouble before. I want 1) no title & 2) instead of the variable values "s1, s2, s3" I want "serotype 1,2,3".

I know i can just relabel the factor but I don't want to do that because I'm stubborn also I don't like having spaces in my variable values

why isn't scale_shape_manual working?

ggplot()+
      geom_point(data=seromelt, aes(x=X, y=value, color=variable, group=variable), 
                 stat= 'identity', size=2, position=position_dodge(width =.2)) + 
      geom_errorbar(data=tbl1, aes(x=X, y=value, color=variable, ymin=value-se, ymax= value+se), 
                    width= 0, size=1, position=position_dodge(width =.2)) +
      ylab("Percent") +
      scale_y_continuous(breaks=seq(0,100,10)) +
      xlab("Health Zone") +
      scale_shape_manual(name="", 
                         breaks= c("s1", "s2", "s3"),
                         labels= c("Serotype 1", "Serotype 2", "Serotype 3")) +
      theme_bw() +
      theme(panel.grid.major.y = element_blank(), 
            axis.text.x = element_text(size=12), 
            axis.text.y = element_text(size=12), 
            legend.text =element_text(size=12)) +
      coord_flip() 

current outcome:

Answer 1

It needs to be scale_colour_discrete. Try this:

 {the rest of ggplot} + scale_colour_discrete(name  = "",
                        breaks=c("s1", "s2", "s3"),
                        labels=c("Serotype 1", "Serotype 2", "Serotype 3"))