The death of a Nebraska man who died in January, about 10 days after receiving his first dose of the COVID-19 vaccine, is under review by the Centers for Disease Control and Prevention.

In a news release Thursday evening, the state Department of Health and Human Services said that the man’s death had been entered into the Vaccine Adverse Event Reporting System, a federal process created to review adverse events following a vaccination.

The man who died was a long-term care facility resident in his late 40s with a number of comorbidities, officials said.

Dr. Gary Anthone, the state’s chief medical officer, said confidence in the safety of the vaccine remains strong.

“While I cannot speculate on this case, when individuals die days or weeks after the vaccine has been administered, it is most likely due to other underlying factors,” he said.

Anthone noted that COVID-19 vaccine deaths “can be attributed to anaphylaxis and occur within a relatively short period after the vaccine is given.” That’s why people who receive the vaccine are monitored for a short period after receiving their shot.

As of Thursday, officials say 258,000 vaccine doses have been administered in the state.​