Increased immunogenicity of recombinant Ad35-based malaria vaccine through formulation with aluminium phosphate...

Area of Science:

• * Virology and Immunology
• * Vaccine Development
• * Parasitic Diseases

Background:

• * Recombinant Adenovirus serotype 35 (rAd35) viral vaccines show promise for inducing immune responses against Plasmodium parasite circumsporozoite protein (CS).
• * Optimizing immunogenicity is crucial for developing effective malaria vaccines.
• * Conventional protein-based vaccines often utilize adjuvants, but their compatibility with viral vectors needs careful consideration.

Purpose of the Study:

• * To evaluate the impact of formulating rAd35.CS vaccine with aluminium phosphate adjuvant (AlPO(4)) on its immunogenicity.
• * To assess the preservation of rAd35 viral infectivity and vaccine stability when combined with AlPO(4).

Main Methods:

• * Formulation of rAd35.CS vaccine with AlPO(4) adjuvant.
• * Assessment of rAd35 viral infectivity in mammalian cells in vitro.
• * Immunization of mice with the formulated vaccine using single and prime-boost regimens.
• * Quantification of CS-specific T and B cell responses.

Main Results:

• * No adverse absorption of rAd35.CS to AlPO(4) was observed, unlike with conventional protein vaccines.
• * In vitro infectivity of the rAd35 viral vector was maintained after formulation with AlPO(4).
• * Significantly higher CS-specific T and B cell responses were achieved in mice immunized with rAd35.CS formulated with AlPO(4) compared to the unadjuvanted vaccine.

Conclusions:

• * Aluminium phosphate (AlPO(4)) adjuvant can be effectively used to enhance the immunogenicity of live Adenovirus serotype 35-based vaccines.
• * This formulation strategy offers a feasible method to increase the potency of rAd35.CS malaria vaccines.
• * The combination preserves viral vector integrity and in vitro infectivity while boosting cellular immune responses.