First Omicron Death in U.S. Was Reinfection—A Warning to Those Who've Already Had COVID

The first confirmed death from the Omicron variant in the U.S. was a reinfection, serving as a warning to people who have already had COVID-19.

Health officials in Harris County, Texas, reported on Monday that a man aged between 50 and 60 had died after testing positive for Omicron.

The man, who was not named, had previously been infected with COVID-19, health officials said. They added that the patient was "at higher risk of severe complications from COVID-19 due to his unvaccinated status and underlying health conditions."

Harris County Public Health Director Barbie Robinson said the man's death was "a reminder of the severity of COVID-19 and its variants."

She added: "Our thoughts and prayers are with the patient's family, and we extend our deepest sympathies. We urge all residents who qualify to get vaccinated and get their booster shot if they have not already."

The man's death came as federal health officials said the highly mutated Omicron variant had overtaken Delta to become the dominant strain of the coronavirus in the U.S. It accounted for 73 percent of new infections last week.

Scientists in southern Africa first sounded the alarm about Omicron less than a month ago and it has since spread to almost 90 countries.

The World Health Organization designated it a "variant of concern" on November 26. The first confirmed case of Omicron in the U.S. was identified on December 1.

Much about the variant remains unknown, including whether it causes more or less severe illness and how easily it spreads.

But a report published by Imperial College London on Friday said researchers found the risk of reinfection from Omicron was more than five times higher than the risk from Delta, suggesting the protection against Omicron afforded by past infection may be as low as 19 percent.

The Imperial researchers also found no evidence that Omicron has been less severe than Delta in the U.K., although they acknowledge that data is limited. Among people who were fully vaccinated and boosted, they recorded a significantly increased risk of developing a symptomatic Omicron case, compared to Delta.

"This study provides further evidence of the very substantial extent to which Omicron can evade prior immunity given by both infection or vaccination," said Professor Neil Ferguson, an epidemiologist at the university. "This level of immune evasion means that Omicron poses a major, imminent threat to public health."

The U.S. Centers for Disease Control and Prevention recommends that everyone over the age of 5 get fully vaccinated against COVID-19 and that those who are over 18 also get a booster shot when eligible.

"Current vaccines are expected to protect against severe illness, hospitalizations and deaths due to infection with the Omicron variant," the CDC says on its website.

"However, breakthrough infections in people who are fully vaccinated are likely to occur. With other variants, like Delta, vaccines have remained effective at preventing severe illness, hospitalizations and death. The recent emergence of Omicron further emphasizes the importance of vaccination and boosters."