Prime/Boost Vaccination using a Mixed Vector Approach - Isis Project No 3991

Oxford researchers have found that priming and boosting immune responses using the same formulation of a pair of different viral vectors can induce strong T-cell responses and overcome anti-vector immunity problems.

Marketing Opportunity

Viral vector vaccines are now widely accepted as a potential solution for some of the world’s most problematic diseases; in fact, many of the leading next generation vaccines for malaria, tuberculosis, influenza and HIV use viral vectors. Such vaccines are also used therapeutically for various cancers. Despite their promise, there is a need to improve the ability of such vaccines to induce potent T-cell immune responses at levels required to provide protective immunity.

The Oxford Invention

Viral vectors engineered to express an antigen of interest have progressed to the forefront of a new generation of vaccines. It is well known that priming with one type of vector and, after a period of time, boosting with another (heterologous prime/boost) elicits increased immune responses, and avoids the problems with anti-vector immunity encountered when using the same vector (homologous prime/boost). However, the heterologous approach requires two separate formulations; a prime and a boost.

Oxford researchers have shown that the administration of an adenoviral and a pox viral vector or two different adenoviral vectors, at the same time or very close together, is remarkably immunogenic and protective. The initial data shows T-cell responses and protection in a mouse malaria model comparable, if not superior, to results with heterologous regimens, and testing in other diseases is underway.

Such mixtures enable the use of lower doses of vectors in a single formulation and, particularly surprisingly, allow the repeated administration of the same vectors while avoiding anti-vector immunity problems.

Patent Status

A UK priority application has been filed. Please contact the Isis Project Manager for further information.

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