On 03 May 2023, the FDA approved Arexvy, the first respiratory syncytial virus (RSV) vaccine approved for use in the United States. Arexvy is approved for the prevention of lower respiratory tract disease caused by RSV in individuals 60 years of age and older.
Also on the 31 May 2023, Pfizer announced that the FDA has approved ABRYSVO™ (Respiratory Syncytial Virus Vaccine), the company’s bivalent RSV prefusion F (RSVpreF) vaccine, for the prevention of lower respiratory tract disease caused by RSV in individuals 60 years and older.
The very first formalin-inactivaed RSV vaccines was developed 60 years ago, but it caused enhanced disease in children when they were subsequently infected with the virus.
Since then, RSV has continued to be a substantial public health threat to infants, young children, and older people. Although progress in developing a new vaccine has been slow and cluttered with setbacks, several recent breakthroughs have brought us not just one, but two promising new RSV vaccines.
There are two major antigenic subtypes of human RSV - A & B. The RSV fusion (F) protein is highly conserved between RSV A and B. The well known Prof Jason McLellan of the University of Texas (one of the inventors of a way to engineer a key protein in coronaviruses for use in vaccines) did much work on RSV protein structures which led to the development of these vaccines.
The scientists at GSK (GlaxoSmithKline Biologicals) developed Arexvy, an RSV vaccine that consists of a purified pre-fusion F protein. The composition is monovalent, meaning that it only contains the F protein of RSV subgroup A. The vaccine is made more immunogenic with addition of an adjuvant – a liposomal formulation that contains two immunostimulants: a derivative of lipopolysaccharide from Salmonella minnesota and a saponin molecule extracted from the bark of the South American evergreen tree Quillaja saponaria.
The researchers at Pfizer came up with ABRYSVO™. This vaccine does not contain an adjuvant and is intended to be administered as a single intramuscular injection to pregnant individuals during the last trimester to protect their infants during the first six months of life. The composition is bivalent, meaning that it contains two copies of the pre-fusion F protein: one from RSV A and one from RSV B.
Finally, a breakthrough after 60 long years.........
Also on the 31 May 2023, Pfizer announced that the FDA has approved ABRYSVO™ (Respiratory Syncytial Virus Vaccine), the company’s bivalent RSV prefusion F (RSVpreF) vaccine, for the prevention of lower respiratory tract disease caused by RSV in individuals 60 years and older.
The very first formalin-inactivaed RSV vaccines was developed 60 years ago, but it caused enhanced disease in children when they were subsequently infected with the virus.
Since then, RSV has continued to be a substantial public health threat to infants, young children, and older people. Although progress in developing a new vaccine has been slow and cluttered with setbacks, several recent breakthroughs have brought us not just one, but two promising new RSV vaccines.
There are two major antigenic subtypes of human RSV - A & B. The RSV fusion (F) protein is highly conserved between RSV A and B. The well known Prof Jason McLellan of the University of Texas (one of the inventors of a way to engineer a key protein in coronaviruses for use in vaccines) did much work on RSV protein structures which led to the development of these vaccines.
The scientists at GSK (GlaxoSmithKline Biologicals) developed Arexvy, an RSV vaccine that consists of a purified pre-fusion F protein. The composition is monovalent, meaning that it only contains the F protein of RSV subgroup A. The vaccine is made more immunogenic with addition of an adjuvant – a liposomal formulation that contains two immunostimulants: a derivative of lipopolysaccharide from Salmonella minnesota and a saponin molecule extracted from the bark of the South American evergreen tree Quillaja saponaria.
The researchers at Pfizer came up with ABRYSVO™. This vaccine does not contain an adjuvant and is intended to be administered as a single intramuscular injection to pregnant individuals during the last trimester to protect their infants during the first six months of life. The composition is bivalent, meaning that it contains two copies of the pre-fusion F protein: one from RSV A and one from RSV B.
Finally, a breakthrough after 60 long years.........
