LONDON — Officials with drugmaker AstraZeneca have asked the U.S. Food and Drug Administration to authorize the emergency use of an antibody treatment to prevent COVID-19.

The company says the treatment, known as AZD7442, will be the first long-acting antibody combination to receive an emergency use authorization for COVID-19 prevention. AstraZeneca says the drug may help protect people whose immune systems don’t fully respond to vaccination.

U.S. demand for antibody treatments soared over the summer, particularly in Florida, Louisiana and Texas, where hospitalizations among unvaccinated patients threatened to overwhelm the health care system.

The drugs are lab versions of virus-blocking antibodies that help fight off infections. The treatments help the patient by supplying concentrated doses. The main antibody treatment used in the U.S. is Regeneron’s dual-antibody cocktail.