people whose immune systems have not been prepared by vaccination.
This distinction is critical when interpreting social-media headlines.
“But My Vaccinated Friend Got COVID”
This is one of the most common arguments people make.
Someone knows a vaccinated person who got COVID.
Perhaps they even know several.
At first glance, that can appear to prove that vaccination doesn’t work.
But individual experiences cannot tell us how effective a medical intervention is across a population.
Imagine a seatbelt.
A person wearing a seatbelt can still be injured in a car accident.
