The Real Deal Against COVID-19

by Danica Nicole Del Rosario (Crypton)

In the search for a vaccine for COVID-19, DNA vaccines may be our best bet.

For several years, we depended on conventional vaccines for preventive immunization against diseases that plagued humanity- measles, hepatitis, polio, and many more- all with due credit to different conventional vaccines. Even so, time also proved it to have limitations, thus, to this day, we are yet to develop cures for HIV, dengue, malaria, cancer and several others. The fastest time taken to employ conventional vaccines, specifically that against Ebola, was five years. Yet, we are seven months amidst a pandemic, and COVID-19 continues to affect millions of people. Containment strategies of governments worldwide are insufficient to flatten the curve of COVID-19 cases. Hypothetically, if vaccine developers generate a safe and efficient conventional vaccine for SARS-CoV-2 in only a year and a half and distribute the vaccine worldwide, then solving the global pandemic will be near our reach. However, the probability of that happening is a low thirty percent, and we cannot wait any longer. Therefore, we consider DNA vaccines as a convincing candidate for a vaccination strategy.

DNA Vaccines are products of Recombinant DNA Technology involving modification through “cutting” and “pasting” of genetic materials in living organisms to join them and produce a novel recombinant DNA with the desired features—one that can now be easily and rapidly cloned to produce many copies in a cost-efficient process. Initially, our immune system responds to the component present in many vaccines: the antigen from the virus we are trying to avoid. The work of vaccines is to facilitate this antigen in the most harmless, nonfatal way possible. Each type of vaccine executes this goal in different ways. Some conventional vaccines use live but weakened viruses, killed viruses, sugars or proteins from viruses, or inactivated toxins from viruses. Still, antigens used by conventional vaccines involve putting whole or parts of the actual virus into our bodies. 

With DNA vaccines, there is no need to insert an actual virus into our bodies—only a “cut” sequence of its genetic material that codes for the antigen. A circular DNA called plasmid is a vector in which the antigen sequence is “pasted” and encoded. The DNA Plasmid is then put into a solution, tested, and administered via several techniques like intramuscular injection, electroporation or particle bombardment using a gene gun. The DNA plasmid reaches the nucleus, undergoes the process of transcription and translation, and antigen synthesis, inducing responses from the B-cells responsible for humoral immunity, and from MHC proteins and T-Cells for cell-mediated immunity. Conventional vaccines only stimulates humoral response. While humoral immunity is necessary for the production of antibodies, cell-mediated immunity is also important for the establishment of long-term immunological memory. 

Broad ranges of immune response induced by DNA vaccines distinguish its potential from the others in producing not only a preventive but also a therapeutic vaccine. But since we are dealing with a problem at hand, SARS-CoV-2, a mutating, rapidly spreading virus that causes COVID-19, The ability of viruses such as SARS-CoV-2 and HIV to undergo antigenic modifications allow these viruses to evade immune response and persist. However, the cloning process provides all kinds of versatility in the DNA vaccine design. It enables immediate manipulation and modification of DNA vaccines to adapt to antigenic variants of the virus, and it also provides potential for integration of different DNA molecules to create a combination of DNA vaccines. 

Since we now know that DNA vaccines offer faster production, cost-efficiency, easy-administration, extensive response, and versatility, the next question is, are they safe? Even if DNA vaccines reach the nucleus of the cell, it does not alter nor incorporate itself into the genome- or the complete set of DNA of an organism- and is consequently not heritable, according to the Professor of Vaccinology in the Nuffield Department of Medicine in the University of Oxford, Sarah Gilbert. According to Grunwald & Ulbert, there are hundreds of volunteers whom received DNA vaccines while experiencing no harmful effects. Cased closed, DNA vaccines will not “turn us into genetically modified organisms” contrary to a similarly harmful “viral” video that circulated last June 2020 with misleading speculations against COVID-19 vaccines.

Although conventional vaccines served us well for years, the urgency called for by the COVID-19 pandemic urges us to find workable solutions apt for the current circumstance. Several studies are in progress to utilize DNA vaccines against HIV, malaria, dengue, cancer, and now, for SARS-CoV-2. With all its advantages, DNA vaccines stand on the forefront of our quest for vaccines to promptly promote herd immunity: a means to protect even the unvaccinated. In the end, that is what DNA vaccines are for—to overcome prevalent health issues by addressing the diseases that conventional vaccines cannot deal with, and more.