How do death rates from COVID-19 differ between people who are vaccinated and those who are not?
Why we need to compare the rates of death between vaccinated and unvaccinated
During a pandemic, you might see headlines like “Half of those who died from the virus were vaccinated”.
It would be wrong to draw any conclusions about whether the vaccines are protecting people from the virus based on this headline. The headline is not providing enough information to draw any conclusions.
Let’s think through an example to see this.
Imagine we live in a place with a population of 60 people.
Then we learn that 10 people died. And we learn that 50% of them were vaccinated.
The newspaper may run the headline “Half of those who died from the virus were vaccinated”. But this headline does not tell us
anything about whether the vaccine is protecting people or not.
To be able to say anything, we also need to know about those who did
not die: how many people in this population were vaccinated? And how many were not vaccinated?
Now we have all the information we need and can calculate the death
rates:
- of 10 unvaccinated people, 5 died → the death rate among the unvaccinated is 50%
- of 50 vaccinated people, 5 died → the death rate among the vaccinated is 10%
We therefore see that the death rate among the vaccinated is 5-times lower than among the unvaccinated.