Abstract: The present invention provides a method for producing pH-stable enveloped viruses wherein said viruses are used for infection of host cells under low pH conditions and for incubation with cell culture cells under conditions of low pH, as well as influenza viruses obtainable by this method which exhibit a high growth rate in cell culture, increased pH and temperature stability and which have human receptor specificity.

Abstract: The present invention provides a method for producing pH-stable enveloped viruses wherein said viruses are used for infection of host cells under low pH conditions and for incubation with cell culture cells under conditions of low pH, as well as influenza viruses obtainable by this method which exhibit a high growth rate in cell culture, increased pH and temperature stability and which have human receptor specificity.

Abstract: The present invention provides a method for producing pH-stable enveloped viruses wherein said viruses are used for infection of host cells under low pH conditions and for incubation with cell culture cells under conditions of low pH, as well as influenza viruses obtainable by this method which exhibit a high growth rate in cell culture, increased pH and temperature stability and which have human receptor specificity.

Abstract: The present invention provides a high growth reassortant influenza A virus having at least two gene segments of seasonal or pandemic strain origin, a PB1 gene segment of A/Texas/1/77 strain origin and a PA gene segment of A/Puerto Rico/8/34 (H1N1) origin coding for a PA protein comprising at least one amino acid modification at any one of positions 10, 275, 682, according to SEQ ID No. 1. Further provided are vaccine formulations comprising the reassortant influenza A virus of the invention.

Abstract: The present invention provides a high growth reassortant influenza A virus having at least two gene segments of seasonal or pandemic strain origin, a PB1 gene segment of A/Texas/1/77 strain origin and a PA gene segment of A/Puerto Rico/8/34 (H1N1) origin coding for a PA protein comprising at least one amino acid modification at any one of positions 10, 275, 682, according to SEQ ID No.1. Further provided are vaccine formulations comprising the reassortant influenza A virus of the invention.

Abstract: The present invention provides a method for producing pH-stable enveloped viruses wherein said viruses are used for infection of host cells under low pH conditions and for incubation with cell culture cells under conditions of low pH, as well as influenza viruses obtainable by this method which exhibit a high growth rate in cell culture, increased pH and temperature stability and which have human receptor specificity.

Abstract: The present invention provides a method for producing pH-stable enveloped viruses wherein said viruses are used for infection of host cells under low pH conditions and for incubation with cell culture cells under conditions of low pH, as well as influenza viruses obtainable by this method which exhibit a high growth rate in cell culture, increased pH and temperature stability and which have human receptor specificity.

Abstract: The invention relates to a simple and efficient process for isolating viruses from various sources and for producing live attenuated influenza vaccines in a serum-free Vero cell culture under conditions where alterations in the surface antigens of the virus due to adpative selection are minimized or prevented. The process does not require purification of the virus-containing supernatant harvested from the cell culture nor post-incubation treatment of the viruses for HA activation. The invention further relates to influenza A and B master strain candidates and to vaccines made thereof.

Abstract: The invention relates to a simple and efficient process for isolating viruses from various sources and for producing live attenuated influenza vaccines in a serum-free Vero cell culture under conditions where alterations in the surface antigens of the virus due to adpative selection are minimized or prevented. The process does not require purification of the virus-containing supernatant harvested from the cell culture nor post-incubation treatment of the viruses for HA activation. The invention further relates to influenza A and B master strain candidates and to vaccines made thereof.