Scientists at Novavax’s headquarters are working on what they think will be another Covid-19 vaccine for the United States and the rest of the world soon.
The results of the vaccine’s large-scale Phase 3 clinical trial in the United States and Mexico are due this month, but the timing is dependent on how rapidly the company collects data on disease prevalence in trial areas.
Dr. Gregory Glenn, president of Novavax’s research and development, told CNN that the company’s vaccine against Covid-19 took a year to develop. Even before the world knew it was struggling with a pandemic, the work began.
Glenn and his colleagues were closely monitoring an unprecedented cluster of pneumonia recorded in China in January of last year. They wondered whether the outbreak was caused by a new strain or recurrence of the coronavirus that causes SARS, or extreme acute respiratory syndrome.
“It occurred to us that this just might be ‘SARS 2,’ ” Glenn said. “The sequence was published on the Internet, the genetic sequence for the virus — and we could see it was a coronavirus. Then we kicked into action.”
Since the SARS-CoV-2 virus, which causes Covid-19, has “spike proteins” on its surface, scientists all over the world easily recognized it as a coronavirus when the sequence was published online. Coronaviruses have large protrusions on their spikes, giving them the appearance of crowns. The Latin word for “crown” is corona.
The virus uses these knob-shaped structures to bind to human cells and infect them. The ability of a vaccine to help protect against Covid-19 depends on the immune system’s ability to identify and “remember” certain spike proteins. However, the manner in which different coronavirus vaccines accomplish this varies.
The NVX-CoV2373 coronavirus vaccine from Novavax differs from the three other coronavirus vaccines currently available in the United States. To induce an immune response and stimulate high levels of neutralizing antibodies, the vaccine uses recombinant nanoparticle technology and Novavax’s adjuvant, Matrix-M.
Novavax scientists identified the gene for the spike protein when the coronavirus genetic sequence was released and produced a modified version of that gene. The genes were cloned into a baculovirus that infects insects, according to the researchers. They then used the virus to infect moth cells, specifically cells from the fall armyworm insect, causing them to develop the coronavirus spike protein.
Novavax’s vaccine was developed using these virus-like nanoparticles.
“The whole idea of the vaccine is to show the immune system something that looks, tastes and acts like a virus, with the exception that it doesn’t make you sick. So we made the spike protein. We put it in a particle — basically, like a soap bubble — and it’s the size of the virus,” Glenn said.
“It’s not infectious. We never touch the coronavirus itself,” he added. “Then that is given to people, and they make an immune response that’s very much focused just on the spike — and I would say, the hallmark of our vaccine is it gives a very strong immune response with very few side effects, and the dose is very small and the vaccine can be stored with normal refrigerated temperatures.”
This is in contrast to the Covid-19 vaccines, which are made with messenger RNA carried in lipids, which are fatty particles. They’re more delicate and must be kept frozen at all times.