It would be interesting to see some sort of comparison between the money poured worldwide into finding a vaccine for this and other vaccine development programmes.
We have been lucky with the way the cards have fallen on this, so it has been worthwhile pursuing a vaccine.
Away from pathogens and into general health for a moment, if we look at, say air pollution from fossil fuels, they cause a lot of health problems. Thankfully we are moving to cleaner solutions, but, we have fossil fuel billionaires with lobbyists fighting change every step of the way. I don’t see a similar situation with SARS-CoV-2, other than anti vax and Jehovah’s Witnesses..
In the case of Pfizer, they basically decided to fund the work themselves, because they can.
For one, there is previous work, which has been relevant, SARS-CoV-1, (which died out on its own) is rather similar to SARS-CoV-2, (our current problem). They both target the same surface proteins to gain entry to cells, ACE2 and TMPRSS2.
https://www.the-scientist.com/news-opinion/receptors-for-sars-cov-2-present-in-wide-variety-of-human-cells-67496SARS-CoV-1 vaccine work got as far as studies in ferrets, (which are quite similar to humans in some ways). There were problems though, the vaccine induced an autoimmune disease. This can happen with infections too, the immune response to the STI chlamydia can lead to reactive arthritis. SARS-CoV-1 disappeared though, and that was that. But the research already conducted has been a springboard for SARS-CoV-2
Piece on the CoV-1 version and comparison to CoV-2
https://theconversation.com/the-mysterious-disappearance-of-the-first-sars-virus-and-why-we-need-a-vaccine-for-the-current-one-but-didnt-for-the-other-137583Another useful feature of SARS-CoV-2 is that it is a disease which produces a noticeable immune response. This is good for us. Diseases which don't do this are hard to produce a vaccine for because the immune system does not seem to particularly notice them. HIV is stealthy like this.
Imagine this, again dodgy analogy..
You are in charge of security at an airport and think you might be attacked by a violent cult.
The Cast: Security = Immune System, Dangerous Cultists = Virus or Bacterium, Actors = Vaccine, Airport = Body.
Lucky for you, there is some intel on them and you know that they always have green mohawks and wear orange jump suits. So you hire actors, dress them up as cultists and stage an exercise where they attack the airport.
Your security people learn to easily spot and respond to these dangerous cultists, so in the event of an attack they mount a robust response and repel the cultists. This is the situation for diseases which cause a robust immune response, (often demonstrated by elevated temperature, swellings, sneezing etc..).
But, now imagine that the intel on your cultists says that they are masters of disguise, they will look like regular passengers. So you hire actors who dress and act like regular airport clients.
The fake cultist actors now enter the airport undetected by security and the security are no wiser on how to recognise them. This is what happens with diseases which do not have a strong immune response, like HIV.
So after your exercise with actors, if REAL cultists attack, dressed as passengers, the security are STILL unable to spot them, they learnt nothing from the exercises. There is no response from them and the cultists can take over the airport without opposition from security.
Finally, the SARS-CoV-2 seems to be reasonably stable to mutation, which means that a vaccine training the immune system to recognise a particular feature of the virus is hopefully going to keep working because the virus will keep having that feature.
The common cold is notorious for its rapid mutation, so while you might learn to recognise it by its green mohawk, the next time it comes around it has long pink hair and slips right by your security. So we don't have a common cold vaccine.
Sorry for this long post, what I am getting at is that pursuing drug or vaccine development will happen if there is a chance of success. Combined with a need for that treatment of course. SARS-CoV-2 has both, hence the development efforts.
