X-ray technician Tim Zook’s health went into a sharp decline after receiving the second shot and he was eventually transferred to the University of California, Irvine Medical Center where he died Jan. 9.
"We are not blaming any pharmaceutical company," Zook's widow, Rochelle, told the Orange County Register. "My husband loved what he did. He worked in hospitals for 36.5 years. He believed in vaccines. I’m sure he would take that vaccine again, and he’d want the public to take it."
"But when someone gets symptoms 2.5 hours after a vaccine, that’s a reaction," she said. "What else could have happened? We would like the public to know what happened to Tim, so he didn’t die in vain. Severe reactions are rare. In reality, COVID is a much more deadly force than reactions from the potential vaccine itself."
The Orange County Coroner confirmed it was investigating Zook's death in a statement emailed to Fox News. Additional tests and autopsy findings will determine the cause of death.
"If it’s determined there may be a correlation to the vaccine, we will immediately notify the OC Health Care Agency," spokeswoman Carrie Braun said in a confirmed statement sent to Fox News.
Zook, 60, worked at South Coast Global Medical Center in Santa Ana, according to the Orange County Register. He posted a photo of his bandaged arm and vaccine card on Facebook and wrote he had "never been so excited to get a shot before. I am now fully vaccinated after receiving my 2nd Pfizer dose."
Several hours later, Zook had an "upset stomach and trouble breathing," and when conditions worsened, work colleagues accompanied him to the ER, the outlet reported. He waved off concerns from his wife, Rochelle, that his issues could possibly be tied to the vaccine.
According to the report, Zook repeatedly tested negative for COVID-19, and was diagnosed with congestive heart failure. He was then allegedly put on a BiPAP machine, the outlet reported. By Jan. 7, Zook was reportedly placed under a medically induced coma and was breathing through a ventilator.
Pfizer and BioNTech said they are aware of the death, and are thoroughly reviewing the matter, per a statement emailed to Fox News.
"Our immediate thoughts are with the bereaved family. We closely monitor all such events and collect relevant information to share with global regulatory authorities. Based on ongoing safety reviews performed by Pfizer, BioNTech and health authorities, BNT162b2 retains a positive benefit-risk profile for the prevention of COVID-19 infections. Serious adverse events, including deaths that are unrelated to the vaccine, are unfortunately likely to occur at a similar rate as they would in the general population."
Rochelle Zook told the Orange County Register that her husband was "slightly overweight but quite healthy." He had high blood pressure, but it had been controlled with medication, the outlet reported.
"The message is, be safe, take the vaccine -- but the officials need to do more research," she told the outlet. "We need to know the cause. The vaccines need to be as safe as possible. Every life matters."
The news comes amid reports of a separate patient in Placer County who tested positive for COVID-19 in late December, was vaccinated Thursday and died several hours after receiving the shot, the Placer County Sheriff's office announced Saturday. That case also involves an active investigation into the cause of death.
It is unclear if the unnamed patient received the Moderna or Pfizer vaccine.
The U.S. Food and Drug Administration gave emergency approval to the vaccine developed by Pfizer/BioNTech only after robust clinical trials and a careful look at safety and efficacy data.
Part of the Biden administrations plan to expedite the vaccination process in the U.S. is to address misinformation about the shots.
Sometimes, vaccine hesitancy comes from a place of misunderstanding, or inaccurate information behind vaccines or the evaluation of their safety, said Dr. William Moss, professor at Johns Hopkins Bloomberg School of Public Health.
The CDC says common side effects from coronavirus vaccines include pain and swelling at the injection site, not unlike other vaccines. Vaccinated individuals may experience fever, chills, tiredness and headache as well. Severe allergic reactions to vaccines are "exceedingly rare," the CDC recently told reporters in a call.
Fox News' Paul Best contributed to this report.