Texas has run out of its supply of monoclonal antibodies, and infusion centers in the state will be unable to offer the treatment until more shipments are sent out in January.

Infusion centers in Austin, El Paso, Fort Worth, San Antonio and The Woodlands have all gone through their supply of sotrovimab, the only antibody treatment believed to be effective against the omicron variant, the Texas Health and Human Services Commission said on Monday.

The agency said infusion centers in Texas will be unable to offer the treatment until "federal authorities ship additional courses of sotrovimab to Texas in January."

"Other monoclonal antibodies have not shown to be effective against the Omicron variant, which now accounts for more than 90 percent of new cases. The infusion centers will continue to offer those antibodies as prescribed by health care providers for people diagnosed with a non-Omicron case of COVID-19," the Texas commission said.

A "limited supply" of the recently approved oral antiviral drugs — one from Merck and Ridgeback Biotherapeutics and the other from Pfizer — will soon be available in Texas, the agency added, noting that the supply of these drugs is also regulated by the federal government.

Health officials began stockpiling doses of sotrovimab this month after studies showed that it was effective against the highly transmissible omicron variant.

On Dec. 17, the U.S. Department of Health and Human Services (HHS) released distribution determinations for sotrovimab, allocating 2,694 doses for Texas. The department said at the time that the government's supply of the antibody treatment was "extremely limited" and additional units would not be available until the week of Jan. 3.

HHS recommended reserving sotrovimab for use in the highest risk outpatients, including patients over the age of 65 and those who are immunocompromised.