From a virologist:
I’m a virologist & investor... & I’m hearing people say it’s impossible to make covid vaccine b/c we haven’t been able to make one to any coronaviruses. Not true. We have veterinary vaccines for dog & cow strains. Human one’s not been investment-worthy, until now. Here’s why.
There are 4 coronavirus strains that circulate amongst humans causing nothing more than mild colds in most people. They stimulate a modest immune response- enough to get over an infection and leave you protected for about a year, maybe more. But eventually antibodies wane, and that’s when you become susceptible to reinfection by same virus.
So why haven’t we developed a vaccine against these 4 coronavirus strains? We could take it every year and protect ourselves against colds, right? That’s a nice idea but most colds are caused by other viruses.
Our four standard human coronaviruses only cause 20% of colds. Colds are mostly caused by rhinoviruses, RSV, parainfluenza virus (not same as influenza), and other viruses we haven’t even identified yet. They are all so different that each would require a different vaccine.
So while we could have made a coronavirus vaccine (which really would have had to be four vaccines, one for each strain), the trouble is that it would have only helped protect you against 20% of the viruses that cause colds.
Even if it reduced your risk of suffering a coronavirus-mediated cold by 75%, that would cut the risk of any cold by only 15% (75% of 20%).
The commercial product people want is not a coronavirus common cold vaccine. They want a COMMON COLD vaccine that protects them against most of their risk. For that, vaccine would have to protect against most cold viruses (and we don’t even know what causes 30% of colds).
[And even if we could develop a universal cold vaccine, it wouldn't be widely used] because 1) it’s just a cold, 2) your insurance would probably make you pay a copay to nudge you into not taking it, 3) people have needles, and here’s the clincher... Anti-vaxxers would tell you that it causes horrors. Some people would get diagnosed with, let’s say, MS or cancer a few days after they got the vaccine simply because that happens to some people by chance at random... it’s a coincidence but anti-vaxxers would blame the vaccine.
But Covid is different. It’s serious, more so than the flu. So we’ll develop a vaccine for it just as we have for the flu and dog/cow coronaviruses. It might cost a few billion dollars across a dozen different programs, but there will be a market.
Just as Sanofi, GSK, & several others companies compete on price & still make billions each year supplying the world with a constantly evolving yet affordable flu vaccine (usually $10-20), similarly industry can develop & supply world w/ a covid vaccine. Maybe even mix it w/ annual flu shot for convenience.
Covid is so technically doable, we already have vaccines for dog & cow coronaviruses. We’ll definitely make one for covid, trials will be simple since we’ll be specifically trying to prevent Covid, which is only caused by SARS-CoV-2 (not by dozen different viruses).