While the symptoms tend to be less severe, can a breakthrough infection still lead to long haul COVID-19?
It's a question ABC7 asked Dr. Chris Colwell, the chief of emergency medicine at Zuckerberg San Francisco General Hospital.
"What we're finding is yes, there are longer symptoms. It is too early to know whether they're similar to those that were infected prior to vaccination," he said.
Dr. Colwell says some of the vaccinated patients haven't had as severe of long haul symptoms as the unvaccinated.
"But there are patients who have been vaccinated and have gotten COVID that are having longer term symptoms," he said.
COVID-19 long haulers endure symptoms like fatigue and confusion months after their diagnosis.
A Stanford study from June found that about 70% of patients hospitalized with moderate or severe COVID-19 suffered from long hauler symptoms months after their initial recovery.
The most common side effects, according to the study, are shortness of breath, fatigue and inability to concentrate, like a brain fog.
During an interview with ABC7 on Monday, Colwell also shared the differences he's seen in COVID-19 patients who are vaccinated versus the unvaccinated.
"This is becoming a pandemic of the unvaccinated," he said.
Dr. Colwell said at his hospital, admitting vaccinated patients into the ICU, intubating them or having vaccinated patients die is "essentially unheard of."
He said the COVID-19 patients in the ICU or those who've died at San Francisco General have almost "exclusively" been unvaccinated.
Watch the entire interview with Dr. Colwell in the media player above. Tune into ABC7's program "Getting Answers" every weekday at 3 p.m.
Map not displaying correctly? Click here to open in a new window.
VACCINE TRACKER: How California is doing, when you can get a coronavirus vaccine
Having trouble loading the tracker above? Click here to open it in a new window.
RELATED STORIES & VIDEOS: