AUSTIN (KXAN) — Five regional infusion centers in Texas have run out of a monoclonal antibody that has shown to be effective against the omicron variant of COVID-19, the Texas Department of State Health Services said Monday.

DSHS said the centers in Austin, El Paso, Fort Worth, San Antonio and The Woodlands have depleted their supplies of the monoclonal antibody called sotrovimab, because of a “national shortage from the federal government.”

Sotrovimab won’t be available at those centers until the federal government ships more of it to Texas in January.

DSHS said people who had appointments to be treated this week will be reached out to directly. As for people with a variant other than omicron, DSHS said the centers will continue offering antibody therapy to those patients as prescribed by health care providers.

The department explained monoclonal antibodies other than sotrovimabhave not shown to be effective against the omicron variant, which is now responsible for more than 90% of new cases.

The Associated Press reports Regeneron and Eli Lilly, both antibody drug makers, recently said lab testing suggests their therapies might be less potent against omicron, “which contains dozens of mutations that make it harder for antibodies to attack the virus.”

The antibody the U.S. is putting focus on, sotrovimab, is provided by Vir Biotechnology and GlaxoSmithKline, and lab studies show it holds up against omicron, according to the Washington Post. The Post reported on Dec. 16 federal health leaders are stockpiling the antibody therapy by deciding to halt every-other-week shipments to states shortly after Thanksgiving.

Texas Gov. Greg Abbott tweeted his displeasure with the Biden administration on Monday.

Omicron became the dominant variant in the country last Monday, according to the Centers for Disease Control and Prevention. Health leaders at the time said data showed nearly a six-fold increase in omicron’s share of infections in only one week.

DSHS points out while two new antiviral pill options to treat COVID-19 will be available soon, the federal government will also control their shipments. Initial supplies are expected to be limited.

Those drugs were authorized last week by the Food and Drug Administration. One pill comes from Pfizer, and the other from Merck.

KXAN found, according to the federal government’s public health emergency page, the first shipments for both pills are scheduled to go out by the end of December. Texas is slated to get 4,240 courses of Pfizer’s pill and nearly 19,800 of Merck’s pills.

DSHS is encouraging people who have COVID-19 and are also high risk to contact their health care provider to talk about treatment options. DSHS is also asking the public to get vaccinated for COVID-19 and get a booster if eligible.