
A new vaccine for Covid-19 that is entering clinical trials in Brazil, Mexico, Thailand and Vietnam could change how the world fights the pandemic. The vaccine, called NVD-HXP-S, is the first in clinical trials to use a new molecular design that is widely expected to create more potent antibodies than the current generation of vaccines. And the new vaccine could be far easier to make.
Existing vaccines from companies like Pfizer and Johnson & Johnson must be produced in specialized factories using hard-to-acquire ingredients. In contrast, the new vaccine can be mass-produced in chicken eggs — the same eggs that produce billions of influenza vaccines every year in factories around the world.
If NVD-HXP-S proves safe and effective, flu vaccine manufacturers could potentially produce well over a billion doses of it a year. Low- and middle-income countries currently struggling to obtain vaccines from wealthier countries may be able to make NVD-HXP-S for themselves or acquire it at low cost from neighbors.
“That’s staggering — it would be a game-changer,” said Andrea Taylor, assistant director of the Duke Global Health Innovation Center.
Vaccines work by acquainting the immune system with a virus well enough to prompt a defense against it. Some vaccines contain entire viruses that have been killed; others contain just a single protein from the virus. Still others contain genetic instructions that our cells can use to make the viral protein.
Once exposed to a virus, or part of it, the immune system can learn to make antibodies that attack it. Immune cells can also learn to recognize infected cells and destroy them.
spike, latches onto cells and then allows the virus to fuse to them.
But simply injecting coronavirus spike proteins into people is not the best way to vaccinate them. That’s because spike proteins sometimes assume the wrong shape, and prompt the immune system to make the wrong antibodies.