A small vial of vaccine packs a powerful punch. Its diminutiveness hides the extensive work that goes behind it. “On an average, it takes 10 long years to develop a vaccine,” says Johannes, who holds a degree in Pharmacy and a PhD in neuro-biochemistry. “If it goes very quick, it takes about four-five years.”
In the case of coronavirus, waiting that long is not an option. Experts contend that a vaccine could come by in 12-18 months but that’s a rather optimistic estimate. Can modern technologies accelerate the process? “Possibly, depending on which concept is the first to find an effective solution,” says Johannes.
The traditional way to develop a vaccine is to isolate the virus, inactivate it and inject it into the human body to trigger an immune response. If such a vaccine has to be produced for billions of people, the virus will have to be grown in large quantities in controlled settings. “You can only imagine the kind of lab facilities, time and resources it would take,” he points out.
Newer ways work with the genetic information of the virus. Before diving into the concepts, we must first understand the basic structure of a virus – each virus particle has genetic material (DNA or RNA), a protective protein cover (capsid), and in cases like the flu virus or the coronavirus, an additional envelope with surface proteins.
The surface proteins protect enveloped viruses from the immune system. When the surface protein recognizes the right kind of host cell, it attaches to it and releases the virus’s genetic material into the cell. As a virus cannot multiply on its own and needs a host cell’s machinery to grow, the surface protein plays the most important role in the survival and propagation of enveloped viruses such as the coronavirus.
Three genome-based key concepts being explored make use of the pathogen’s genetic information, for example the parts that direct the production of these surface proteins, elaborates Johannes.
In the first kind of genome-based vaccine, part of the virus’s genetic material is inserted into a vector, which is transferred to bacteria or cells that produce the viral surface protein that is used as vaccine.
In the second kind, part of the virus’s genetic material is inserted into harmless carrier viruses, which are then injected into humans to ‘teach’ the body to respond appropriately to the real threat.
In the third type, the viral RNA itself is delivered to the body as a vaccine. The RNA directs the production of parts of the viral surface proteins. The vaccinated person's cells produce the viral protein from this RNA, which then triggers an immune response.
“Such genome-based vaccines can be developed and produced much quicker than traditional vaccines,” Johannes says. However, they need to be tested thoroughly before being rolled out to the public. “A vaccine is not a 100 percent bullet against any virus. Plus, the safety aspect cannot be underestimated. Just because a vaccine was found safe in 100-200 people during the trials doesn’t mean it is safe for 5 billion plus people,” he warns.