SAN ANTONIO — At least a dozen Walmart locations around San Antonio indicate they're stocked with newly-approved COVID-19 antiviral pills.
The Texas Department of State Health Services says the drugs, made by Pfizer and Merck, officially became available Thursday.
The new treatment arrived in Texas just days after five regional infusion centers, including San Antonio's Freeman Coliseum, ran out of the only monoclonal antibody therapy that stifles the omicron variant of the coronavirus.
"I am inclined to think those pills will be used to treat the omicron variant until we're certain we have a new monoclonal antibody preparation that's effective against Omicron," said Dr. Fred Campbell, internal medicine physician at UT Health San Antonio.
Sotrovimab, the working antibody treatment, is now in high demand and short supply. Texas officials do not expect to receive more doses from the federal government until mid-January.
Other antibody treatments are still available, but are rendered virtually useless.
"Monoclonal antibodies are developed to attack certain parts of the COVID-19 virus," Campbell said. "The virus will mutate by changing those proteins, so the monoclonal antibody no longer recognizes them as foreign proteins."
Just five antibody preparations are currently authorized for use in the United States. Sotrovimab is the only version that appears to be effective against omicron.
Scientists are trying to engineer new antibody preparations specifically for the new, highly contagious variant.
Antiviral medications offer a benefit slightly different from antibody treatment.
The pills aim to interfere with the virus's ability to replicate. While acting as a sort of distress signal for other immune responses, antibody infusions bond to the viral cells so they cannot infect a human's cells.
"The pills are more like traditional antiviral agents that deactivate a lot of the processes in the viral cell," Campbell said.
Infected patients cannot get Merck's or Pfizer's pills without a prescription. Merck's, in particular, may carry some risk for pregnant women.
Talk to a doctor about your medical history before obtaining a prescription.