Roughly a third of the US population has gotten at least one dose of a COVID-19 vaccine.
The authorized shots available from Pfizer, Moderna, and Johnson & Johnson - which are being given out free of cost to all adults across the US - are both safe and effective at stopping COVID-19 infection, hospitalization, and death.
To build that immunity, the body has to be trained (by a vaccine) to recognize the coronavirus, in order to fight it. For some people, that process feels like nothing. But many feel some side effects in the days after their shot, as the immune system gets to work.
Common side effects include a sore or swollen arm, headache, fever, chills, fatigue, and nausea. These symptoms can last a few days after each shot.
To get a sense of how common and long-lasting these effects can be, the Centers for Disease Control and Prevention has developed a text message-based symptom tracker program called v-safe.
I enrolled in the program after my first vaccine dose. Here's how it works: