Advancements in the medical field in the last decade have been made possible by the advent of newer vaccine forms. The vaccine forms are subunit vaccines, DNA vaccines, and recombinant vaccines among others. Even though these vaccines have been effective in the past decade, researchers and clinicians have associated them with many disadvantages. They are expensive to afford and are also difficult to store and transport. Many countries that are still under development have had challenges in facing these issues.  Therefore alternative forms of vaccines that are cheaper and efficient had to be developed by researchers. The development of edible vaccines was successful as an alternative vaccine form.

Langridge in his book titled ‘ Edible Vaccines’ reveals that edible vaccines generate through genetic plant transfer as well as transgenic animal production made up of agents that tend to trigger the immune system of the animal. Edible vaccines produced from these plants have been known by researchers to be of great importance. Charles J. Arntzen in the 1990s came up with the concept of edible vaccines through his research (Langridge, 2006). This idea was as a result of the World Health Organization conference that he attended in New York. Sophisticated research ideas and scientific concepts have been put to place to ensure the success of this idea. The growing of tomato plants and bananas at the Boyce Thompson Research Institute for plant research has produced vaccines. This production was as a result of genetically engineering them to obtain immunizations from their fruits. The widespread growth of bananas and tomatoes made it easy for them to be preferred as edible vaccines (Langridge, 2006). The vaccines would not require any syringes since they are edible.

According to a similar publication by Kumar and Chaitanya, edible vaccines have also been seen to be of great importance as well. The expression of a surface antigen from streptococcus bacterium mutants present in tobacco was the earliest demonstration of an edible vaccine. The stimulation of the immune response of the mucosa was found to prevent the colonization of the bacteria in the teeth as well as teeth decay even though the bacterium is responsible for tooth decay (Chaitanya and Kumar, 2006). DNA fragments found in the original pathogen exist in edible vaccines. The DNA fragments are responsible for protein coding. The eliciting of the body’s immune system is then made possible by this protein-coding.

An Example of edible vaccines includes transgenic potatoes for the case of diarrhea.  In 1997, the first trial of the vaccine on human beings was carried out. Some volunteers consumed the transgenic potatoes which contained vast amounts of b-subunit of E.coli heat-labile toxin. This element is responsible for causing diarrhea. A fourfold increase in the serum antibodies of 10 patients out of 11 was detected by researchers (Chaitanya and Kumar, 2006). Using this form of the vaccine is however disadvantageous since it has to be consumed in raw form. The protein may denature in the cooking process. Half of the vaccine remained alive through partial boiling.

Edible vaccines protect when the M-cells absorb an antigen in food in the intestine and directed to other immune system cells. This process then forms a defensive attack, leaving a group of ‘memory’ cells which then neutralize the infectious agent in an attempt of invasion. The memory helper T-cells when a disease occurs, generate T-cells which are cytotoxic and attack the cells already infected (Langridge, 2006). The memory helper T-cells also stimulate the secretion of antibodies. The antibodies, in turn, neutralize the invader which is the infection.

Edible vaccines are cheap meaning that manufacturers can produce them in bulk. They do not need any purification process since people mostly eat them raw. They also trigger the immunity found at the surfaces of the mucosa like the ones lining the mouth which is the first line of defense in the body. It is, however, difficult to control the vaccine dose of these edible vaccines. Research has shown that high dosage can lead to bacteria invasion instead of immune response. The dosage between adults and children is entirely different (Chaitanya and Kumar, 2006). The change of plants as living organisms also does not guarantee the continuity of the vaccine.

In conclusion, the creation of the inexpensive vaccines has made a great journey since the first trial of edible vaccines in 1997. The vaccines have by so far been effective and are less costly than the other initial alternative vaccine forms. Even though they have minor disadvantages, future innovations are more likely to make them the most effective means of vaccination as they are cheaper and easily affordable.

References

Langridge, W. H. R. (2006). Edible Vaccines. Scientific American Special Edition, 16(4), 46–53. https://doi.org/10.1038/scientificamerican1206-46sp

V.Chaitanya, K., & Ujwal Kumar, J. (2006). Edible vaccines. Retrieved from https://www.sriramachandra.edu.in/university/pdf/research/journals/sep_2006/book_8.pdf