1/A recurring refrain I hear about #COVID19 #vaccines is, "Why should I get the shot since I can still get COVID after?"
I want to discuss why that isn't exactly an accurate assessment why it doesn't accord with the way that most of us think about risk in our daily lives.
I want to discuss why that isn't exactly an accurate assessment why it doesn't accord with the way that most of us think about risk in our daily lives.
2/Let's start with the core notion: that you can still get #COVID19 after being fully #vaccinated.
That is true. But the statement lacks critical context. While you can still get COVID after getting a vaccine, you are MUCH less likely to do so.
The relative risk matters.
That is true. But the statement lacks critical context. While you can still get COVID after getting a vaccine, you are MUCH less likely to do so.
The relative risk matters.
3/At baseline, the #COVID19 vaccines have an effectiveness of around 80-90%.
Vaccine effectiveness is a measure derived from clinical trials and calculates the relative risk of being affected in a vaccinated population vs. an unvaccinated one.
cdc.gov/vaccines/covid…
Vaccine effectiveness is a measure derived from clinical trials and calculates the relative risk of being affected in a vaccinated population vs. an unvaccinated one.
cdc.gov/vaccines/covid…
4/Breakthrough cases can and do occur. And as more people in #Maine get vaccinated, there will be more breakthrough cases.
That is not alarming, nor is it, on its own, evidence of vaccine failure. In a world with 100% vaccination, all new cases would be breakthrough cases.
That is not alarming, nor is it, on its own, evidence of vaccine failure. In a world with 100% vaccination, all new cases would be breakthrough cases.
5/What matters is the overall rate of cases among vaccinated people and unvaccinated. That is, your relative risk.
And there, the numbers are reassuring. Roughly 99% of all fully vaccinated people in Maine have *not* experienced a breakthrough case.
And there, the numbers are reassuring. Roughly 99% of all fully vaccinated people in Maine have *not* experienced a breakthrough case.
6/Another element is the severity of illness when vaccinated vs. unvaccinated people get #COVID19.
In short, vaccinated are less likely to get COVID and, if they do, their severity of illness (measured by hospitalization and vent use) is attenuated.
jamanetwork.com/journals/jama/…
In short, vaccinated are less likely to get COVID and, if they do, their severity of illness (measured by hospitalization and vent use) is attenuated.
jamanetwork.com/journals/jama/…
7/An earlier study found the same: being #vaccinated reduced the likelihood of #COVID19, the viral load, risk of symptoms, and duration of illness. nejm.org/doi/10.1056/NE…
8/The relative risk is what matters.
On a population level, #COVID19 dramatically lowers the risk of illness & hospitalization. These data, from @CDCgov, show that vaccinated people have a 6.1X lower risk of COVID, and an 11.3X lower risk of death.
covid.cdc.gov/covid-data-tra…
On a population level, #COVID19 dramatically lowers the risk of illness & hospitalization. These data, from @CDCgov, show that vaccinated people have a 6.1X lower risk of COVID, and an 11.3X lower risk of death.
covid.cdc.gov/covid-data-tra…
9/The same trend holds for hospitalizations, where vaccinated adults have a 9X lower risk of hospitalization than unvaccinated ones.
Does vaccine eliminate the risk? No. But it significantly lowers it, which is what they are designed to do.
covid.cdc.gov/covid-data-tra…
Does vaccine eliminate the risk? No. But it significantly lowers it, which is what they are designed to do.
covid.cdc.gov/covid-data-tra…
10/But all of this misses a more fundamental point: this isn't how most people go about their lives.
There is no drug, device, procedure, test, or scan in the history of medicine that is 100% effective and durable for all people in all conditions at all times.
There is no drug, device, procedure, test, or scan in the history of medicine that is 100% effective and durable for all people in all conditions at all times.
11/If you're approach to medicine is dichotomous (i.e., "If it doesn't work 100% of the time, then I don't want it."), then what part of modern medicine are you on board with?
If a 9X reduction in hospitalization isn't compelling, what would be?
If a 9X reduction in hospitalization isn't compelling, what would be?
12/No antibiotic is 100% effective in every situation, but I can't imagine someone with severe pneumonia saying, "You know, the pneumonia could still rage on even with this antibiotic, so I'll pass."
13/We don't routinely hear people say such things because we all understand that what matters is *relative* risk reduction.
This is the notion that we can be better off with an intervention compared with the status quo, even if that intervention isn't 100%.
This is the notion that we can be better off with an intervention compared with the status quo, even if that intervention isn't 100%.
14/Indeed, this is how most people go about their lives.
You can still be injured in a car accident when you have a seat belt on, but your likelihood of doing so is MUCH lower.
You can still be injured in a car accident when you have a seat belt on, but your likelihood of doing so is MUCH lower.
15/Your house can still have a fire even with a smoke detector installed, but I don't see people regularly tossing out their detectors.
You can still fall after you've shoveled your sidewalk in the winter, but we all think it's a good thing to do nonetheless.
You can still fall after you've shoveled your sidewalk in the winter, but we all think it's a good thing to do nonetheless.
16/Again, we do these things recognizing that none offers absolute protection.
We do them because they reduce the relative risk. Vaccines are the same.
We do them because they reduce the relative risk. Vaccines are the same.
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