tldr: no.
There are a few pathogens that are so contagious, almost everyone in a population gets it, if they haven't been vaccinated. Measles is like that, so is chickenpox. But in most cases, it's only a fraction.
The human genome is 99.9% the same for all of us, but most of the 0.1% difference is in genes related to infection. We are all descended from people who managed to not die of rampant infectious disease.
For example, about 1% of Americans are immune to contracting HIV, and another 10% have a gene that allows them to keep the virus at low enough levels to remain asymptomatic for decades. 20% of the population is immune to the stomach flu. For a long time, the pathogen Mycobacterium leprae was thought to be two pathogens, because there are two ways the human immune system can respond to it, and each person's immune system picks one or the other. If your immune system picks the wrong one, you have chronic leprosy.
To make things even more complicated the immune system changes with age. Children are more susceptible to allergies; adults are more susceptible to chronic inflammation, and that inflammation is probably a factor here.
People tend to think that this is mostly about how "strong" your immune system is, but in both the HIV and stomach flu, the resistance gene is a change in the virus receptor.
With covid-19, we already know that older people are more susceptible to becoming infected, as are those with certain blood types.
We also have the case of the cruise ship, where a group was probably all exposed to some degree, as they were locked up for a month with infected people. If we look at just those over 50, about 80% never got the virus at all. 10% got it, but didn't have symptoms. 9-ish% got it and were sick but survived, and about 0.2-0.3% got it and died.
It's possible that if the 80% who didn't get it had been exposed to a higher dose, they might have gotten it. I suspect that part of the reason the Chinese doctor died of it at 34 was that he was probably exposed to a massive dose of virus, while simultaneously experiencing high stress from being a whistleblower and extreme sleep deprivation from caring for too many very sick patients.
But there is also most likely a genetic difference in how different people's immune systems are responding, and how the virus is interacting with their cells.
How many people will become infected depends on how well we socially distance and quarantine the exposed and infected, how the virus responds to warming temperatures, etc. But it is unlikely to be everyone. Given the case of the cruise ship, it's probably not even going to be the majority.
ETA: If 20% of us get it, and 2% of those that get it die, that's still 1.3 million Americans dead. So not as bad as it could be, but still bad.
There are a few pathogens that are so contagious, almost everyone in a population gets it, if they haven't been vaccinated. Measles is like that, so is chickenpox. But in most cases, it's only a fraction.
The human genome is 99.9% the same for all of us, but most of the 0.1% difference is in genes related to infection. We are all descended from people who managed to not die of rampant infectious disease.
For example, about 1% of Americans are immune to contracting HIV, and another 10% have a gene that allows them to keep the virus at low enough levels to remain asymptomatic for decades. 20% of the population is immune to the stomach flu. For a long time, the pathogen Mycobacterium leprae was thought to be two pathogens, because there are two ways the human immune system can respond to it, and each person's immune system picks one or the other. If your immune system picks the wrong one, you have chronic leprosy.
To make things even more complicated the immune system changes with age. Children are more susceptible to allergies; adults are more susceptible to chronic inflammation, and that inflammation is probably a factor here.
People tend to think that this is mostly about how "strong" your immune system is, but in both the HIV and stomach flu, the resistance gene is a change in the virus receptor.
With covid-19, we already know that older people are more susceptible to becoming infected, as are those with certain blood types.
We also have the case of the cruise ship, where a group was probably all exposed to some degree, as they were locked up for a month with infected people. If we look at just those over 50, about 80% never got the virus at all. 10% got it, but didn't have symptoms. 9-ish% got it and were sick but survived, and about 0.2-0.3% got it and died.
It's possible that if the 80% who didn't get it had been exposed to a higher dose, they might have gotten it. I suspect that part of the reason the Chinese doctor died of it at 34 was that he was probably exposed to a massive dose of virus, while simultaneously experiencing high stress from being a whistleblower and extreme sleep deprivation from caring for too many very sick patients.
But there is also most likely a genetic difference in how different people's immune systems are responding, and how the virus is interacting with their cells.
How many people will become infected depends on how well we socially distance and quarantine the exposed and infected, how the virus responds to warming temperatures, etc. But it is unlikely to be everyone. Given the case of the cruise ship, it's probably not even going to be the majority.
ETA: If 20% of us get it, and 2% of those that get it die, that's still 1.3 million Americans dead. So not as bad as it could be, but still bad.
