Most people diagnosed with the omicron variant of COVID-19 that U.S. health officials followed up with experienced mild infections, according to a new report from the Centers for Disease Control and Prevention.
Out of the 43 cases with initial follow-up, there was one hospitalization and no deaths reported, the CDC said Friday. Twenty-two states have reported at least one case of the omicron variant of the coronavirus, also known as B.1.1.529, as of Wednesday.
“Many of the first reported cases of omicron variant infection appear to be mild, although as with all variants, a lag exists between infection and more severe outcomes, and symptoms would be expected to be milder in vaccinated persons and those with previous SARS-CoV-2 infection than in unvaccinated persons,” the CDC researchers wrote in their report. “Even if most infections are mild, a highly transmissible variant could result in enough cases to overwhelm health systems. The clinical severity of infection with the omicron variant will become better understood as additional cases are identified and investigated.”
Twenty-five of the cases, or 58%, were reported in people ages 18 to 39, the CDC researchers found. The earliest symptom onset from the strain occurred on Nov. 15 in a person who had traveled internationally. Fourteen people, or 33%, reported traveling abroad during the 14 days before experiencing symptoms or receiving a positive test result.
Thirty-four people with the omicron variant, or 79%, included in the study had finished the primary series of an approved COVID-19 vaccine two weeks or more before experiencing symptoms or testing positive for the coronavirus. Of those, 14 individuals had received an additional vaccine dose, including five who had gotten boosters less than two weeks before experiencing symptoms.
Six people, or 14%, had a previous COVID-19 infection. Cough, fatigue and congestion or a runny nose were the most commonly reported symptoms, the report said. A vaccinated patient was hospitalized for two days.
The cases have been linked to international and domestic travel, large public events and household transmission.
The first case of the omicron variant was identified on Dec. 1 in California. Since then, cases of the strain have been reported in Arizona, California, Colorado, Connecticut, Florida, Georgia, Hawaii, Illinois, Louisiana, Maryland, Massachusetts, Minnesota, Mississippi, Missouri, Nebraska, New Jersey, New York, Pennsylvania, Texas, Utah, Washington state and Wisconsin, the CDC said.
In late November, the Biden administration suspended entry for noncitizens who had been in eight countries in southern Africa where the variant was spreading — Botswana, Eswatini, Lesotho, Malawi, Mozambique, Namibia, South Africa and Zimbabwe — during the two weeks before traveling to the U.S. The CDC on Dec. 2 amended the travel order to require COVID-19 testing for all international air passengers traveling to the U.S. On Dec. 6, the order changed to cut down the time to obtain a negative COVID-19 test result to no more than one day before a flight’s departure.
The World Health Organization labeled the omicron strain as a “variant of concern” on Nov. 26, with the U.S. SARS-CoV-2 Interagency Group following suit on Nov. 30.