International medical experts have been working tirelessly for months trying to develop a SARS-CoV-2 vaccine that is safe and effective for humans. Dr. David B. Weiner, director of the Vaccine & Immunotherapy Center, believes that the current race for a COVID-19 cure may result in a breakthrough in genetic vaccines.
Conventional vaccines work by injecting antigens to trigger the body's immune response to a virus or bacteria. DNA vaccines are genetically altered and placed within a protein shell, or a capsid, containing the genetic code of antigens.
Back in 1983, scientists Enzo Paolettia and Dennis Panicali fro the New York Department of Health created recombinant DNA vaccines by combining cowpox DNA with genes from other viruses in hopes to transform the smallpox vaccine into a cure for other diseases as well.
Today, the modern 'father of DNA vaccines' is David Weiner, who cofounded the biotech firm Inovio. On May 20, they announced the clinical study of their coronavirus DNA vaccine, INO-4800, which they had developed in March.
They may the first company to have a DNA vaccine available in the market, Although they are not under the government's chosen companies for Operation Warp Speed, the INO-4800 is the only DNA vaccine that is stable at room temperature for over a year.
Vaccines containing genetic code has the potential to become international front-runners in developing a cure for the pandemic. Inovio will soon announce the results of their first human trials for INO-4800.
'I think we should set our expectations low," shared Weiner on managing expectations. 'I really think we're most likely to have several vaccines, and that they will lower disease severity and prevent some infections. It doesn't have to be 100% effective to have enormous value for the world.'
His work began nearly 30 years ago, Weiner and some colleagues contemplated developing a viral gene that transfers instructions from DNA to RNA to produce the antigen to fight infection. This became a possibility for the coronavirus when Chinese scientists published the virus' entire genetic code by January. The next step would be delivering the DNA into cells, technology which Professor Weiner pioneered at the University of Pennsylvania during the early 1990s.
Now, scientists have observed that bacteria carry plasmids or loops of DNA separate from the chromosomal DNA which replicates independently. Plasmids help bacteria resist antibiotics. Developing the DNA vaccine includes equipping plasmids to carry antigen genetic code into the human body. Weiner said, 'we look for nature to teach us what to do.'
However, DNA vaccines aren't as effective as RNA vaccines, causing giant biotech firms to abandon these kinds of developments. Very few plasmids would find their way into cells that trigger the immune system against the virus and not itself.
'A lot of big boys and girls left the field,' said Joseph Kim, the co-founder and CEO of Inovio. 'One who persisted, by conviction or stubbornness or both, was Dave Weiner.'
Currently, the company has 15 vaccine developments in clinical testing for cancer and infectious diseases, including human trials for Middle East Respiratory Syndrome (MERS). 'It's going to take many technologies crossing the finish line to make an impact in the face of SARS-CoV-2,' said Weiner, 'and we hope our technology can be part of the solution.'