Cotton rats were immunized with 107 pfu rVSV-F, rVSV-G, or rVSV-G-2A-F via subcutaneous route, and then boosted with the same dose via the same route 4 weeks later. Cotton rats were challenged with RSV-A2 after a total of 7 weeks, and viral titers were assessed via TCID50, with the limit of detection at 2log10. Serum antibody levels were assessed via neutralizing antibody assay, with the limit of detection set at 10. A. Neutralizing titers against RSV in serum. Group rVSV-G-2A-F generated statistically significant higher titers of neutralizing antibodies. B. RSV titer in lung homogenate. rVSV-F, rVSV-G, and rVSV-G-2A-F immunization provided partial protection against RSV A2 challenge. C. RSV titer in nasal turbinate homogenate. rVSV-F and rVSV-G-2A-F immunization provided partial protection against RSV A2 challenge. * p<0.05, ** p<0.01, *** p<0.001, **** p<0.0001