Respiratory Syncytial Virus Vaccine Development

Respiratory Syncytial Virus Vaccine Development

Respiratory syncytial virus, first identified in 1952, is the cause of a severe lower respiratory disease that kills nearly 200,000 people worldwide each year. Respiratory syncytial virus can cause bronchiolitis in infants and young children, as well as severe respiratory illness in the elderly and immunocompromised adults. The virus is mainly transmitted through close contact with saliva or mucous droplets. Respiratory syncytial virus infection usually manifests as an upper respiratory tract (URT) infection that persists for several days before the virus enters the lungs.

Overview of Respiratory Syncytial Virus

Respiratory syncytial virus belongs to Pneumovirus, subfamily Pneoumovirinae, family Paramyxoviridae, and contains an approximately 15.2 kb unsegmented, non-segmented negative-stranded RNA. The full-length genome was segmented into 10 genes encoding 2 nonstructural and 9 structural proteins. Nonstructural proteins are involved in evading innate immune responses, and structural proteins F and G are the major antigens expressed on the surface of virions and the most important targets for neutralizing and protective antibodies.

Schematic diagram of the respiratory syncytial virus virion and its genome structure. (Shang Z, et al., 2021)

Respiratory Syncytial Virus Treatment

The development of respiratory syncytial virus vaccines has been challenging for a number of reasons, including the ability of the virus to prevent the host from activating adaptive immunity, and the multiple ways in which respiratory syncytial virus evades/suppresses innate immunity. Currently, there are no approved treatments for respiratory syncytial virus infection. The preclinical and clinical development of respiratory syncytial virus intervention can be roughly classified into three categories: monoclonal antibodies, small molecule inhibitors, and vaccines.

• Antibodies
  Antibody therapy is an important preventive treatment for patients at risk of severe respiratory syncytial virus infection. Respiratory syncytial virus virions contain F, G and SH surface proteins, of which the F protein is highly conserved among respiratory syncytial virus strains and is the main target of protective neutralizing antibodies.
• Molecule Inhibitors
  At present, the development of small molecule inhibitors for the treatment of respiratory syncytial virus infection is mainly based on two modes: one is to prevent the binding of invading virus particles to the F protein on the surface of respiratory syncytial virus, and the other is to inhibit the transcription and replication of the virus to inhibit the new virus particles. produce. The nucleoside analog ribavirin is the only antiviral inhibitor clinically approved for the treatment of respiratory syncytial virus infection.
• Vaccines
  For decades, it has been increasingly recognized that the development of effective vaccines to protect at-risk populations from severe respiratory syncytial virus infection is essential. The most basic principle of respiratory syncytial virus vaccine design - respiratory syncytial virus neutralizing antibodies need to be introduced into the airway mucosa in the most rational way. Currently, dozens of promising vaccines are in development to prevent respiratory syncytial virus infection. Mainly attenuated vaccines, subunit vaccines, vector vaccines, DNA vaccines, virus-like particle (VLP) vaccines and other vaccines.

Respiratory Syncytial Virus VLP Vaccines

VLPs are recombinantly produced particles composed of multiple copies of selected proteins. These particles are also safe as they are made up of only proteins and do not contain a viral genome and therefore cannot replicate.

VLPs of respiratory syncytial virus. (Quan FS, et al., 2011)

What Can We Do

As an expert in building VLPs from VLPlant^TM platform, CD BioSciences uses its expertise to help our clients develop respiratory syncytial virus vaccines. We are good at customizing our services according to the needs of our clients. Please contact us if you are interested.

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References

1. Shang Z.; et al., Respiratory syncytial virus: from pathogenesis to potential therapeutic strategies. Int J Biol Sci. 2021, 17: 4073-4091.
2. Quan FS.; et al., Viruslike particle vaccine induces protection against respiratory syncytial virus infection in mice. Erratum in: J Infect Dis. 2012,205: 520-528.