[1] RSV affects an estimated 64 million people and causes 160,000 deaths worldwide each year.
[2] The RSV vaccines Arexvy (GSK),[3] Abrysvo (Pfizer),[4] and Mresvia (Moderna)[5] are approved for medical use in the United States.
[4][7][19][20][21][22] Abrysvo is approved for use in pregnant women at 24 through 36 weeks and older adults in the European Union.
[26] This vaccine induced vaccine-associated enhanced respiratory disease, in which children who had not previously been exposed to RSV and were subsequently vaccinated would develop severe RSV disease if exposed to the virus itself, including fever, wheezing, and bronchopneumonia.
[29][30] A 2013 study detailed the crystal structure of the RSV fusion (F) protein and how its stability could be improved.
[33][34] In April 2023, the Committee for Medicinal Products for Human Use of the European Medicines Agency (EMA) recommended to grant a marketing authorization for Arexvy for the prevention of RSV lower respiratory tract disease in people 60 years of age or older[35][36] after review under the EMA's accelerated assessment program.
[37][38] In May 2023, the FDA's expert panel unanimously recommended Abrysvo for approval in pregnant women.
Since 2023, Abrysvo has been approved for the prevention of lower respiratory tract disease caused by RSV in individuals 60 years of age and older and for use in pregnant individuals at 32 through 36 weeks gestational age for the prevention of lower respiratory tract disease and severe lower respiratory tract disease caused by RSV in infants from birth through six months of age.
[16][49] In November 2020, GSK's vaccine, GSK3888550A, entered phase III trials for pregnant women.
[60] The FDA analyzed data from an ongoing, randomized, placebo-controlled clinical study conducted in the US and internationally in individuals 60 years of age and older.
[37] The main clinical study was designed to assess the safety and effectiveness of a single dose administered to individuals 60 years of age and older.
[65] In April 2023, Pfizer published their interim results of their phase III study of a RSV vaccine for adults age 60 and older in over 34,000 participants.
The vaccine's protection was consistent across different subgroups, and was 62% effective in preventing acute respiratory illness caused by RSV infection.
[21] In a subgroup of pregnant individuals who were 32 through 36 weeks gestational age, of whom about 1,500 received Abrysvo and 1,500 received placebo, Abrysvo reduced the risk of lower respiratory tract disease by 34.7%, and reduced the risk of severe lower respiratory tract disease by 91.1% within 90 days after birth when compared to placebo.