Combination Ad26.RSV.preF/preF protein vaccine induces superior protective immunity compared with individual vaccine...

Area of Science:

• Vaccinology
• Virology
• Immunology

Background:

• Respiratory syncytial virus (RSV) causes significant respiratory illness globally.
• Currently, no licensed vaccine is available for RSV prevention.
• Previous studies indicated immunogenicity and protection from individual RSV vaccine components.

Purpose of the Study:

• To evaluate the immunogenicity and protective efficacy of a combination vaccine against RSV.
• To assess the contribution of each component to the overall immune response.
• To support the clinical development of a novel RSV vaccine candidate.

Main Methods:

• A combination vaccine comprising a prefusion (preF) conformation-stabilized RSV F protein antigen and an adenoviral vector (Ad26.RSV.preF) was administered in a single injection.
• Humoral and cellular immune responses were measured in RSV-naïve and pre-exposed mice and African green monkeys (AGMs).
• Protective efficacy was assessed in cotton rats following challenge with RSV A2.

Main Results:

• The combination vaccine strongly induced both humoral and cellular immune responses in mice and AGMs.
• Both vaccine components contributed to humoral immunity, while Ad26.RSV.preF was the primary driver of cellular immunity.
• The combination vaccine provided superior protection against RSV challenge in cotton rats compared to single components.

Conclusions:

• A combination vaccine strategy for RSV is advantageous.
• This combination vaccine elicits robust immune responses and significant protection.
• The findings support further clinical investigation of this RSV vaccine candidate.