Millions experience side effects from COVID-19 vaccine. What if you don’t?
As millions now know from personal experience, the COVID-19 vaccines can cause temporary side effects. It’s a good sign, as it suggests your immune system is paying attention, preparing you in case of infection with the coronavirus.
But if you don’t experience side effects, does that mean the vaccine did not work?
Good news: The short answer is no, infectiousdisease experts say. There is no evidence that a lack of side effects means the vaccinated person is unprotected against COVID-19.
The details require a bit of explanation, but the main reason physicians feel comfortable making that statement is simply math.
In the clinical trials, less than half of vaccine recipients reported moderate or severe episodes of “systemic” side effects such as fever, headache, and fatigue. Yet the drugs prevented most cases of disease, according to those studies. So by the process of elimination, some of that disease prevention must have occurred in the people with mild or no side effects.
“The vaccines still work even if you don’t have side effects,” said Sarah Coles, a family physician and assistant professor at the University of Arizona College of Medicine. “While many have side effects, many do not.”
To put it another way, both phenomena — acquiring immunity and experiencing side effects — are set in motion by the same series of inflammatory warning signals in the immune system once you get injected.
Whether people experience side effects might be determined by other factors besides their immune systems, including fatigue, stress and how they perceive pain, Coles said.