Up until now SARS-CoV-2 has caused the death of 5 million people, a significant number of animals (no exact number has been reported) whereas the rest of us are trying to protect ourselves with the available traditional subcutaneous vaccines. Our goal as a team is that the edible vaccine we have developed will be accessible in the near future for veterinary and human use. In order to apply our project to the real world, specific safety aspects need to be considered and challenges to be overcome.

Why should someone prefer an edible vaccine over a conventional one?

Vaccines are substances that stimulate the immune system to recognize and respond to antigens. During the last two decades, a new type of vaccination has been developed that has the ability to minimize the risks associated with traditional immunizations. The gene-encoding bacterial or viral disease-causing agent can be integrated into plants without losing its immunogenic activity in the creation of edible vaccines. Edible vaccines work by inducing systemic and mucosal immune responses against a foreign pathogen. By inserting a transgene into a specific plant cell, edible vaccinations can be created. Currently, edible vaccines for veterinary and human use are being developed. However, the biggest problem that edible vaccines confront is public acceptance. It is vital to educate the public about the use and benefits of edible vaccines and this is where iGEM Crete comes forward with our Human Practices activity program. Edible vaccines are more cost-effective, efficient, and safe than conventional traditional immunizations. It promises to be a better disease prevention solution.

End Users

As the COVID-19 pandemic established and deteriorated the world’s health systems, economy and the population’s overall well being, we witnessed an increasing gap on vaccine distribution in developed versus developing countries. This gap was no surprise to us as there has repeatedly been recorded a neglect of developed countries regarding urgent prevention and therapy public health measures. Therefore, we thought we would prevent such a situation escalating again with the current pandemic by developing a vaccine suitable to the needs and conditions of developing countries. To achieve this goal we carefully studied previous vaccine strategies in a few developing countries and arranged meetings with people who could enlighten us on this topic. From our research we came to the conclusion that creating a product which would necessarily have to be shipped from the USA or Europe to Africa and the Middle East etc would make no difference from the previous strategies, as the shipping cost is still a major obstacle in vaccine distribution. This is why an edible vaccine would be appropriate for overcoming this problem as it can be produced with minimal equipment in the place where it is needed. Of course we needed to adjust to the weather conditions, everyday life and health providing systems of these areas but this was a journey we were more than happy to explore.

Ethical Issues and Obstacles in the Approval of Edible Vaccines for Human Consumption

The World Health Organisation (WHO) held a meeting in January 2005 to discuss the regulatory examination of plant-based vaccines. The meeting came to the conclusion that the established rules for the creation, evaluation, and use of conventionally produced vaccines can be applied to the manufacturing of edible vaccines. There were a number of concerns around edible vaccines. Plant-derived vaccines should be clinically studied under a US investigational new drug application, and all regulatory and Good Manufacturing Practices (GMP) criteria must be followed.
The use of edible vaccines in humans is contingent on a number of factors. It must be well-accepted by the general public, thus society must be educated on the use and benefits of edible vaccinations. As for the vaccine itself, the stability of genetically modified plants must be accessible, as well as sufficient plant isolation. If created properly, edible vaccines have the potential to be a superior disease prevention alternative to conventional vaccination methods. Simultaneously, the cultivation of plants for the development of edible vaccines necessitates constant monitoring. Even if the manufacturing of genetically modified plants is thoroughly being supervised, ensuring the safety and quality of these plants will be tough. After extensive research and several clinical studies, we expect that our idea will be suitable for animal and eventually human use in the future.

Alternative solution: Animal consumption

Several species have been tested positive for SARS-CoV-2. Cats and dogs, felines in zoos or sanctuaries, gorillas in zoos, minks on farms, and a few other mammals are all prominent hosts. The special COVID-19 edible vaccine will be a good option for immunizing animals because the cost will be minimal and administration will be simple. Avoiding the exposure of these animals to SARS-CoV-2 prevents the development of new animal reservoirs and future spillovers of the virus to humans. Overall, edible vaccines should be viewed as a viable and rapid alternative for reducing SARS-CoV-2 transmission rates as well as the prevalence of a future pandemic disease!

Steps for the approval of such an immunization method

After we complete the proof of concept, our invention must be scientifically evaluated by regulatory agencies such as the European Medicines Agency (EMA), the United States Department of Agriculture (USDA), and the Food and Drug Administration agency (FDA) before it can be used in the real world. Plant-based vaccines must be evaluated in terms of growth, manufacturing, and purification. Furthermore, manufacturers must adhere to Good Agricultural Practices (GAP) and Good Manufacturing Practices (GMP) in order for the quality to be consistently excellent. Furthermore, in order for the quality to be constant, manufacturers must follow Good Agricultural Practices (GAP) and Good Manufacturing Practices (GMP). Clinical trials will follow quality tests to determine the vaccine's effectiveness, safety, and adverse effects.
Hopefully, after receiving approval from the government, mass production will begin. This step necessitates the use of skilled and experienced personnel who will monitor the manufacturing processes in specifically constructed facilities where seedlots are kept distinct from other materials. For this reason, preventative measures should be taken right from the outset of the manufacturing process. We hope as iGEM Crete team that our project will someday be available to humans as a prevention method to the different variants of SARS-CoV-2.

Safety and Challenges of our project

Plants that have been genetically modified usually relate to the stable insertion of a transiently expressed gene. Our team had to evaluate the health dangers and ethical difficulties that would arise from the intake of such a plant because our end result is an edible (for humans and other vertebrates) vaccine. As a result, rather than creating a GMO plant, we opted to build lettuce leaves that could express our protein via transient expression. If our plant is released into the environment, this strategy reduces any counter-effects inside the organism and controls the likelihood of toxicity, antibiotic resistance, or any other side-effects. The lettuce leaves will only express our spike protein for a short time, only long enough to change immunity. Lactuca sativa leaves expressing the chimeric protein should also not be left out in the environment because they could be eaten by any animal, with unknown consequences.
Since we are using agroinfiltration, the Lactuca sativa (lettuce) leaves that will be transiently expressing our chimeric protein cannot be considered a GMO, but they should be treated as such.


In order to avoid any potential underdose or overdose, we must also calculate the dosage range. Before administering, factors such as a person's weight, age, fruit/plant size, maturity, and protein level must be determined. A low dosage can result in poor antibody production, whereas a higher dosage can result in tolerance.
The determination of dosage numbers and potential use of mucosal adjuvants will be known after the results of the immunization experiments in vertebrates.


As mentioned above, the main obstacle that our team, as well as the entire scientific community, must overcome is public acceptance in its totality. Many people fear that GMOs endanger both humanity and the environment. Our mission is to inform the public by offering scientific proof of the benefits of the plant we invented, as well as debunking any myths that contradict the facts. Looking back on what we've accomplished throughout this difficult year, we believe that even if only a small number of people have gained a better understanding of GMOs' prospects, we, nevertheless, consider this a great win!
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