Inactivation of extracellular enveloped viruses in blood and blood components by phenthiazin-5-ium dyes plus light

A method for inactivating extracellular enveloped viruses which are present in a leukocyte-containing, red blood cell-containing composition, comprising:

• (a) leukodepleting said composition;
• (b) adding an adequate amount of at least one phenothiazin-5-ium dye to said composition to produce therein an effective concentration of said dye(s), wherein said concentration is acceptable for transfusion and wherein said concentration in conjunction with light is effective to inactivate extracellular enveloped viruses contained in said composition;
• and
• (c) irradiating said phenothiazin-5-ium dye-containing composition for an effective length of time, with light of an effective intensity and of wavelengths which are absorbed by said dye(s), whereby said irradiation in conjunction with said dye(s) inactivate extracellular enveloped viruses in said composition, wherein said red blood cells retain their viability.

A method for inactivating extracellular enveloped viruses which are present in a leukocyte-containing, platelet-containing composition, comprising:

• (a) leukodepleting said composition;
• (b) adding an adequate amount of at least one phenothiazin-5-ium dye to said composition to produce therein an effective concentration of said dye(s), wherein said concentration is acceptable for transfusion and wherein said concentration in conjunction with light is effective to inactivate extracellular enveloped viruses contained in said composition;
• and
• (c) irradiating said phenothiazin-5-ium dye-containing composition for an effective length of time, with light of an effective intensity and of wavelengths which are absorbed by said dye(s) whereby said irradiation in conjunction with said dye(s) inactivate extracellular enveloped viruses in said composition, wherein said platelets retain their viability.

A method for inactivating extracellular enveloped viruses which are present in leukocyte-containing plasma, comprising:

• (a) leukodepleting said plasma by a factor of at least 5 log.sub.10 ;
• (b) adding an adequate amount of at least one phenothiazin-5-ium dye to said leukodepleted plasma of step (a) to produce therein an effective concentration of said dye(s), wherein said concentration is acceptable for transfusion and wherein said concentration in conjunction with light is effective to inactivate extracellular enveloped viruses contained in said composition;
• and
• (c) irradiating said phenothiazin-5-ium dye-containing plasma of step (b) for an effective length of time, with light of an effective intensity and of wavelengths which are absorbed by said dye(s), whereby said irradiation in conjunction with said dye(s) inactivate extracellular enveloped viruses in said plasma.