Context

• The Food and Drug Administration (FDA) approved the first vaccine Arexvy vaccine for respiratory syncytial virus (RSV) to lower respiratory tract disease in people older than 60 years.

• This is the first RSV vaccine to be approved anywhere in the world.

Key Details

• The vaccine is manufactured by the company, GSK, and the FDA approval was based on a phase-3 trial carried out on nearly 25,000 participants.
• According to the U.S. Centres for Disease Control and Prevention, lower respiratory tract disease caused by the RSV virus leads to approximately 60,000-1,20,000 hospitalisations and 6,000-10,000 deaths among adults who are 65 years of age and older.
• The RSV virus significantly affects older adults with comorbidities. Like the common cold, the RSV usually causes mild symptoms but can turn deadly if it infects older people.
• Besides older adults, infants too are at high risk from RSV.
• Two more vaccines for RSV by Pfizer and Moderna have already completed clinical trials on adults older than 60 years and may soon be approved by the FDA. While the vaccine developed by Pfizer is protein-based, Moderna has used mRNA technology, like in the case of the SARS-CoV-2 vaccine, to develop the RSV vaccine.

All about Arexvy

• Arexvy contains a recombinant subunit prefusion respiratory syncytial virus F glycoprotein antigen (RSVPreF3) combined with GSK’s proprietary AS01E adjuvant, the London-based pharmaceutical firm said in a statement.
• Recombinant subunit vaccines are the ones manufactured by inserting defined protein antigens into other cells, such as yeast cells, in order to produce a large number of subunits.
• The antigens are usually genetic codes of the targeted virus, and are purified, which means they will not be pathogenic to the person receiving the vaccine, and will instead illicit an immune response.
• Prefusion stabilisation is a technique that increases the recombinant expression of viral fusion glycoproteins, by preventing misfolding, according to a study published in the journal Science.
• Viral glycoproteins are integral parts of enveloped viruses, and fusion (F) glycoprotein is an important part of the respiratory syncytial virus. The F glycoprotein mediates fusion of the viral and cell membranes to allow the virus to enter the host cell and initiate a new infectious cell.
• Therefore, using this antigen inside the respiratory syncytial virus vaccine will allow the immune system of the host organism to produce antibodies against the F glycoprotein, and allow them to neutralise virus particles in the wake of a future infection.

About Respiratory syncytial virus

• Respiratory syncytial virus (RSV), also called human respiratory syncytial virus (hRSV) and human orthopneumovirus, is a common, contagious virus that causes infections of the respiratory tract.
• It is a negative-sense, single-stranded RNA virus.
• Its name is derived from the large cells known as syncytia that form when infected cells fuse.
• RSV is the single most common cause of respiratory hospitalization in infants, and reinfection remains common in later life: it is a notable pathogen in all age groups.
• Infection rates are typically higher during the cold winter months, causing bronchiolitis in infants, common colds in adults, and more serious respiratory illnesses such as pneumonia in the elderly and immunocompromised.

How is the virus spread?

• Respiratory syncytial virus is air-borne as well as fomite-borne. It is transmitted through coughing and sneezing, through direct contact with an infected individual, or by touching objects with the virus on it.

Source: TH

Visit Abhiyan PEDIA (One of the Most Followed / Recommended) for UPSC Revisions: Click Here

IAS Abhiyan is now on Telegram: Click on the Below link to Join our Channels to stay Updated 

IAS Abhiyan Official: Click Here to Join

For UPSC Mains Value Edition (Facts, Quotes, Best Practices, Case Studies): Click Here to Join