Scientists from the Institute of Experimental Medicine (IEM, St. Petersburg) have completed preclinical trials and prepared a line of innovative edible vaccines for submission to the Russian Ministry of Health. The platform, based on genetically modified probiotics, includes about eight preparations against various viral and bacterial infections.
Probiotics as the Foundation of the Mucosal Platform
The technology is unique as it uses probiotics — beneficial lactic acid bacteria (specifically, enterococci) that are natural to the human microflora and traditionally used in the fermentation of sour-milk products — as vectors for antigens.
Through genetic engineering, a DNA fragment of a virus or pathogenic bacterium is inserted into the genome of such a probiotic bacterium. Once in the body, the modified probiotic produces target antigens on its surface. This makes it possible to form a robust immune response directly on the mucous membranes (the so-called mucosal immunity), which are the primary gateway for most infections.
According to Alexander Suvorov, Head of the Molecular Microbiology Department at IEM and Academician of the Russian Academy of Sciences (RAS), the probiotic basis allows the preparation to be produced in the form of capsules (dried granules) or a regular sour-milk product tasting like kefir or ryazhenka. Moreover, the production cycle eliminates the complex stage of chemical synthesis and additional purification, making the scaling process potentially more cost-effective.
Development Portfolio and Comprehensive Solutions
Research on beneficial microorganisms has been conducted at IEM for over 15 years; however, the development of the vaccine platform specifically began in 2021 with the creation of an edible COVID-19 vaccine (the preparation is currently updated for the relevant Omicron strain). To date, the institute’s portfolio has expanded to eight variants.
“To date, we have created about eight different such probiotic variants that can protect not only against viral diseases but also against various pathogenic bacteria. One such development is a complex two-component vaccine that contains antigens of the influenza virus and pneumococcus, which very often aggravates the development of viral diseases.”
— Alexander Suvorov, Head of the A.A. Totolyan Molecular Microbiology Department at IEM, Academician of the RAS
The current pipeline also includes:
- Coronavirus infection vaccine;
- Two variants of the influenza vaccine;
- Pneumococcal infection vaccine;
- Three variants of the vaccine against group B streptococcus (a pathogen capable of causing severe complications in newborns).
Global Experience and Oral Vaccine Development
The global experience with oral vaccines encompasses both classic preparations and modern experimental platforms based on genetically modified plants and microorganisms.
- Classic solutions: The foundation for this field was laid by the Sabin oral polio vaccine and inactivated cholera vaccines (e.g., Euvichol and Euvichol-S), used by the WHO for mass prevention.
- Plant-based platforms: Since the 2000s, experimental vaccines based on transgenic plants (bananas and potatoes with polio antigens, as well as tomatoes and rice) have been tested worldwide. In Japan, a powdered cholera vaccine made from genetically modified rice has proven its safety, and in Uzbekistan, an edible TOMAVAC vaccine against COVID-19 based on transgenic tomatoes has been developed.
- Advantages and barriers: The key advantages of such vaccines include the absence of injections, the simplicity of mass vaccination, the possibility of room-temperature storage, and overall cost reduction. However, their widespread implementation is hindered by lower immunogenicity compared to injectable analogs, as well as strict GMO regulatory requirements.
Russian Project Status
To date, the IEM’s baseline technology has passed a full range of preclinical trials (in vitro and in laboratory animals), confirming the efficacy and safety of the edible vaccines. In the near future, the dossier will be submitted to the Ministry of Health of the Russian Federation to obtain official approval to launch clinical trials involving volunteers.
Project Summary
| Parameter | Details |
|---|---|
| Developer | Institute of Experimental Medicine (IEM, St. Petersburg) |
| Number of preparations | Around 8 vaccines |
| Target pathogens | COVID-19, influenza virus, pneumococcus, group B streptococcus |
| Vaccine basis | Genetically modified probiotics (lactic acid bacteria) |
| Dosage form | Sour-milk product or capsules (granules) |
| Mechanism of action | Activation of mucosal immunity (via mucous membranes) |
| International analogs | TOMAVAC (Uzbekistan, tomato-based), rice-based cholera vaccine (Japan) |
