Hypothetically, let's say, in December of 2020, all the leading world health organizations announce that there will be a Covid vaccine that will be available for distribution starting January 1, 2021. A lot of people would be thinking, that means, life goes back to normal starting in January, but I don't think many people have actually thought this through in terms of the reality of what a vaccine would mean.
Our planet currently has roughly 7.5 billion people on it, all of whom would presumably need a vaccine. Now we know from vaccine programs for things like the flu, not everyone actually needs a vaccine if you get to the threshold where we develop herd immunity. Herd immunity, or community immunity, comes about when a certain percentage of the population is vaccinated to the point where there aren't enough active carriers of the virus to allow for rampant unchecked spread.
So how do we get there? Comparing it to the flu and what is required for herd immunity, we would need roughly 50%-70% of the population to be vaccinated so if we luck into that 50% number, that still means 3.75 billion people worldwide would need this vaccine. Currently, in the US, the CDC reports that it can produce 198 million flu vaccines for US consumers before they begin to run out of supply or 1.5 billion worldwide....so....you can kind of of see where this is not going.
Then, what no one wants to start thinking about is who will actually get the vaccine first or at all? We can kind of nudge kids out of the way since they are shown to be least affected by Corona, so that knocks 2.2 billion out worldwide leaving us still with 5.3 million ish who would still need a vaccine (there is still no official confirmation with medical science that those who have had Covid can't get it again---see Influenza). One could reasonably argue that front line workers will be the first to get vaccines, but after that, it basically seems like it will be a free for all...
...but we all know the bottom line of this all too. These companies who manufacture these medications and vaccines and pills are notorious for wanting a "give me an arm and a leg" cut. Humanitarianism be damned! It is not likely this will be free or affordable for a majority of people considering there will be a limited supply. You can't make this vaccine $20, 50, or maybe even $100 a pop, because then anybody would have easy access to it which creates an overwhelming pressure on the supply/demand chain which will already exist in an extreme in this case because everyone is basically vulnerable to Corona.
Then you must add to that the time it will take to get people vaccinated. It won't be like, this whole office or this whole neighborhood all gets shots, so 10% of your co-workers at your job may be lucky enough to get vaccines by the time 2021 ends, but that isn't enough to return to life as we know it. So as with everything in the world, let the discrimination start---those that got their vaccines, free to start new life, those that haven't gotten one, stay at home and away from everyone else. Along with that discrimination will invariably come corruption and abuse of power with those at the top hoarding and supplying their families and friends rather than their nations and those most vulnerable with vaccines or overcharging delaying the potential get of herd immunity.
So if you're excited that all our problems will be solved with a vaccine if it comes in 2021, I wouldn't bet on that. You want to feel hopeful with the start of a new year, and feel like things can be better with a vaccine, but the reality is, it may be the year after that or that where we are finally at a place where we can actually treat Corona like the flu and live our lives.