Feligen RCP Dosage and administration Reconstitute the vaccine with 1 ml of the diluent provided or Leucogen and inject the contents of one vial aseptically by the subcutaneous route. Primary course vaccination In cats of 9 weeks or over, two doses of Feligen RCP, administered 3 to 4 weeks apart will stimulate full active immunity. Revaccination scheme A single dose of Feligen RCP is recommended annually to maintain maximum immunity to FIE, FVR and calicivirus.