The former head of the US Food and Drug Administration, Dr. Scott Gottlieb, has warned that vaccinating Americans against the new coronavirus is more critical than ever, especially as the new South Africa variant appears to inhibit antibody drugs.

“The South Africa variant is very concerning right now because it does appear that it may obviate some of our medical countermeasures, particularly the antibody drugs,” said the former FDA chief in the Trump administration in an interview on CNBC’s “The News with Shepard Smith” on Tuesday evening. “Right now that strain does appear to be prevalent in South America and Brazil, the two parts of the world, right now, that are in their summer, but also experiencing a very dense epidemic, and that’s concerning.

The South African variant is also known as 501.V2, and in mid-December officials reported that 501.V2 had been largely replacing other strains of the coronavirus as early as November. South Africa has already sustained the more than 1.1 million infections and more than 30,000 deaths, the most on the African continent.

Gottlieb cited experimental evidence from Bloom Lab, and explained 501.V2 does appear to partially escape prior immunity. It means that some of the antibodies people produce when they get infected with the coronavirus, as well as the antibody drugs, may not be quite as effective.

“The new variant has mutated a part of the spike protein that our antibodies bind to, to try to clear the virus itself, so this is concerning,” Gottlieb said. “Now, the vaccine can become a backstop against these variants really getting more of a foothold here in the United States, but we need to quicken the pace of vaccination.”

A sign at Groote Schuur Hospital in Cape Town, South Africa, indicating a coronavirus testing station Tuesday, December 29, 2020.

South Africa coronavirus variant appears to inhibit antibody drugs.