Ohio and Rhode Island on Saturday became the 28th and 29th states to report cases of the Omicron virus variant.
Ohio officials said two cases were detected, both of which were among persons who were fully vaccinated more than six months ago.
Rhode Island officials confirmed one case. The patient is fully vaccinated and recently returned from New York.
Over half of the states in the country have confirmed cases of Omicron, a variant of the CCP (Chinese Communist Party) virus, which causes COVID-19.
Across 29 states, 110 cases have been reported as of Saturday.
Officials disclosed the vaccination status of 66 of the infected individuals. Of those, the vast majority, or 52, were fully vaccinated. Some had even gotten booster shots.
Most of the Omicron cases in the United States have been among the vaccinated, the Centers for Disease Control and Prevention (CDC) said in an update on Friday. Most patients have experienced mild symptoms, and some have recently returned from trips from Africa or been in contact with somebody else who had.
No deaths from Omicron have been reported anywhere in the world since Omicron was identified by South Africa scientists last month.
Early data indicates the variant, when compared to earlier strains, transmits more easily, can better evade the protection bestowed by vaccines, and may be able to better evade natural immunity, or protection from prior infection.
But COVID-19 cases caused by Omicron have been on average less severe.
Few U.S. patients have required hospitalization so far, according to reports from state health authorities and the CDC.
Cases have been confirmed in Arizona, California, Colorado, Connecticut, Florida, Georgia, Hawaii, Louisiana, Idaho, Illinois, Iowa, Maryland, Massachusetts, Minnesota, Missouri, Nebraska, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, Texas, Utah, Virginia, Washington state, and Wisconsin.
Approximately 61 percent of the U.S. population was fully vaccinated as of Saturday, according to federal data. About a quarter of the population had gotten a booster shot, including over half of those in the most vulnerable population, adults 65 or older.
In South Africa, even as the number of tests went up, the number of positives dropped along with hospital admissions, health authorities reported on Saturday.
That was the opposite trend as that seen in the United States, where cases, hospitalizations, and deaths have gone up during the week.
Omicron quickly became the dominant strain in South Africa, but in the United States, over 99 percent of cases are still from the Delta variant, CDC head Dr. Rochelle Walensky told reporters in a virtual briefing.
Some health officials are still urging people to get vaccinated, with an emphasis on booster shots.
An interim analysis from Pfizer and BioNTech found their shot plummeted in effectiveness against Omicron but that a booster restored some of the protection.
That was “a striking endorsement of the importance of boosting,” said Dr. Anthony Fauci, the longtime head of the National Institute of Allergy and Infectious Diseases.
A study from Israeli researchers out Saturday reached a similar finding.
“People who received the second dose 5 or 6 months ago do not have any neutralization ability against the Omicron,” Gili Regev-Yochay, director of the Infectious Diseases Unit at Sheba Medical Center, told reporters in Jerusalem. “The good news is that with the booster dose it increases about a hundred fold,” she said, though the boosted neutralization ability was still four times lower than the protection against the Delta variant.
