Vaccine technologies: Why a Covid vaccine will take months, not centuries

The smallpox virus raged among humans for 10,000 years before a leap of insight led to the vaccine that killed it forever. The insight took about 300 years to develop.
Today, in the wake of the Covid crisis, drug companies throughout the world are experimenting with vaccines. One company, Moderna, took 42 days to create an experimental vaccine.
Why so fast?
The most obvious reason is the research infrastructure: Laboratories, drug companies, medical systems — systems we take for granted — have never before been available on such a wide scale. Humans are in the era of science and technology.
Still, of the seven known coronaviruses, there are no known human vaccines.
According to Johns Hopkins Senior Scholar Dr. Amesh A. Adalja, the key to the new rapid development of vaccines is new vaccine platform technologies. Writing in, Adalja says these platforms use the same building blocks to make more than one vaccine. Using the basic platform, researchers are able to, in effect, switch out one targeted virus (or bacteria or other organism) like a person switches out a video game cartridge. One example of that is the ebola vaccine, which uses another virus as a platform with the ebola protein inserted.
A variety of different approaches are being used to create a Covid vaccine. Moderna is using an RNA approach. Inovio is using a DNA model in which genetic material is injected into the platform and human cells translate it into a viral protein. At that point the immune system makes antibodies.
Other approaches include nanoparticles (by Novavax), while other companies try to adapt an avian coronavirus vaccine.
According to Adalja, a coronavirus vaccine could possibly confer protection against other human coronaviruses, eliminating their use as a biological threat in the future.
And, even curing the common cold.