Is my COVID-19 vaccine working if I don’t have side effects?

Infectious disease specialist: You don't have to get sick from vaccine to be immune

A portrait of Dr. Wendell Hoffman

With more people getting a COVID-19 vaccine every day, more reports are available on possible side effects.

Sore arms are the most common reaction, said Wendell Hoffman, M.D., an infectious disease specialist at Sanford Health. That reaction is about as common and as tolerable as reactions to flu and tetanus shots, he said.

Other less commonly reported side effects include flu-like symptoms: headache, fatigue, fever or chills, for 24-48 hours. That’s a natural immune response, Dr. Hoffman said. But what if you don’t feel any side effects?

“If you get this vaccine and you don’t experience any side effects, it doesn’t mean that it’s not initiating a strong immune response,” he said.

The first COVID-19 vaccines use messenger RNA to trigger an immune system response as if your body had an infection.

When you get a vaccination, your body reacts with an army of immune responders called B-cells and T-cells, Dr. Hoffman said. B-cells are like archers, special ops strikers that attack the perceived threat from afar by sending antibodies. T-cells are like foot soldiers, directly engaging the threat with spears, swords and shields.

If your antibody levels are low, don’t forget about the rest of the army of T-cells. They work together to make you immune, Dr. Hoffman said.

He added that vaccination is the safest way to achieve herd immunity — meaning enough people are vaccinated to protect more vulnerable people from getting sick. And possible side effects shouldn’t keep you from getting vaccinated.

“Don’t be afraid of the COVID vaccines,” he said. “They are safe, they are effective, and you are doing your fellow human beings a great service by becoming vaccinated yourself. People mistakenly say that I am on the front line. Actually, everybody is on the front line. And so,  you have to view it that way: In order to really defeat a virus, we have to be in this all together.

“All of us are on the front line in a pandemic.”

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Posted In Coronavirus, Frequently Asked Questions, Immunizations