RSV Flashcards
RSV vaccine
Bivalent RSVpreF/ABRYSVO
protects infants until 6 months of age
Recombinant bivalent RSV A& B stabilised perfusion F proteins
MATISSE phase 3 trial - 82% efficacy at 3 months and 70% at 6 months after maternal vaccination
Single dose @ 32 to 36 weeks.
Older adults: AReSVi study - adults > 60 received single dose.
25,000 participants. Efficacy 82% against RSV. 94% against severe disease. Similar efficacy for RSV A&B.
Nirsevimab
Long acting mAb. binds to the prefusion conformation of the RSV fusion (F) protein, i.e. it binds to the site at which the virus would attach to a cell.
Single dose lasts for 5 month.
NOT co-administered with palivizumab.
MELODY STUDY - 75% reduction of Medically attended-RTI
CDC - 90% reduction in hospitalisation.
Palivizumab
Recombinant humanised mAb against F-protein on surface of RSV.
Up to 5 IM doses 15mg/kg monthly intervals over the RSV season (beginning of Oct to end of Feb).
JCVI - at risk infants:
1. Pre term infants with BPD(CLD) who meet criteria from table (based on gestational and chronological age) or term infants with Resp diseases on ventilation
2. Pre term infants with CHD who meet criteria from table
3. Infants < 2 years with SCID
Effectiveness - 55% reduction in hospitalisation.
RSV structure & classification
Enveloped (-)ssRNA
Family: Pneumoviridae (previously paramyxo)
Genus: Orthopneumovirus
10 genes encoding 11 proteins
Envelope proteins: G - host cell attachment
F - Fusion & cell entry
SH protein
Single RSV serotype with 2 antigenic subgroups A&B
Humans are the ONLY host
Baltimore: V
RSV clinical picture
Primary infection:
URTI
LRTI - bronchiolitis, croup, pneumonia
Otitis Media
Reinfectioj milder
RSV receptors & incubation
G protein - annexin II, CX3CR1 (endothelial cells)
F protein - TLR4, ICAM-1(bronchial epithelial cells)
Incubation: 3-5 days
RSV treatment & vaccines
Ribavirin nebulised - FDA approved in brinchiolitis
Palivizumab & Nirsevimab
Vaccine - Bivalent recombinant vaccine
GSK - Arexvy - adjuvant PreF protein vaccine
Pfizer - Abrysvo - RSV pre-fusion F maternal vaccine
RSV vaccine rollout UK
1 September 2024: 2 vaccines being rolled out by NHS - ABRYSVO for pregnant & ARESVI for older adults.
All adults turning 75 years old on or after 1 September 2024 will be eligible for the routine programme and should be offered a single dose of the RSV vaccine on or after their 75th birthday.
All women who are at least 28 weeks pregnant (the eligible cohort) on 1 September 2024, should be offered a single dose of the RSV vaccine, through commissioned services. After that, pregnant women will become eligible as they reach 28 weeks gestation and remain eligible up to birth.
Clesrovimab
RSV monoclonal - binds to the conserved site IV of the RSV F glycoprotein
