[Animats]

Messenger RNA vaccines, which are a new technology, turned out to work much better than expected. They can be synthesized fast. It took two days to make the first mRNA vaccine molecules for coronavirus. Traditional vaccine technology is slower. Bulk production was a problem; encapsulating those fragile mRNA molecules without breaking them requires a difficult bit of microfluidics technology. But it's difficult in the sense that IC manufacturing is difficult. Once the manufacturers got the tooling and the process right, it worked well.

Here's the list of vaccines under development.[1] There are 105 different vaccines in the pipeline. Most of those are more traditional approaches and don't work yet, need further testing, don't work as well, or have other problems. What we have now is the minimum viable product - two doses, difficult handling and distribution, requires an injection. Some of the ones in the pipeline are skin patches, nasal sprays, or pills. The Merck pill, though, turned out to be a dud - provides only weak protection.

The non-injection schemes may help overcome some of the vaccine resistance problems.

Throwing money at the problem did help. Usually, vaccine R&D consists of finding the most likely candidate, setting up the Phase I/II/III trials, and waiting to see how it works. If it doesn't work, the developers go on to another candidate. Developing 100 different vaccines in parallel improved the odds. A lot.

[1] https://www.nytimes.com/interactive/2020/science/coronavirus...