The functional role of CD4+ T cells for the generation of neutralizing antibodies or direct antiviral protection was further reflected by survival rates of mice after lethal i. c. challenge with CVS-11: All mice vaccinated with Rabipur (undepleted positive control) survived the challenge infection while buffer injected mice (negative controls) had to be sacrificed by day nine post challenge due to dramatic weight loss (Fig 5C). This evidence concerns the gene CD4 and infection.