Introduction

Use of the microorganism Leishmania as a vaccine vehicle against coronaviruses. Thanks to the use of this new vehicle it is possible to deliver the antigens in an efficient and targeted way to the cells of the immune system responsible for their presentation (APC). The main vaccines against viruses belonging to the Coronaviridae family do not provide for a targeted delivery of the antigen to the APCs and lymph nodes and this can limit the generation of long-term immunological memory.

Technical features

To date, all the vaccines developed to contrast SARS-CoV-2, as well as other coronaviruses, are able to fight the virus but present some issues: they do not allow the development of an efficient long-term immunological memory; furthermore they present a greater risk of developing an inflammatory pathology in case of subsequent infections. The innovative vaccine is developed using as vehicle Leishmania tarentolae, a single-cell microorganism not pathogenic for humans, which is engineered to express the antigens stimulating the production of antibodies that neutralise the virus in the vaccinated subject. The advantage of this vehicle is that, once administered also in an inactivated form, having a specific tropism for APCs, it is therefore able to carry the antigen directly into these cells, a phenomenon that allows to generate a more efficient long-term immunological memory and to minimise the induction of an inflammatory response.

Possible Applications

• Vaccine against SARS-CoV-2 (pre-clinical validation phase);
• Vaccine against other coronavirus.

Advantages

• Targeted delivery of the antigen to the cells responsible for its presentation (APCs);
• Limited pro-inflammatory response in the lymph node;
• Long-term immunological memory;
• Ease of production.