5 things travelers need to know about the mu COVID-19 variant

As Americans grapple with the surge of COVID-19 cases thanks to the delta variant, a new variant is becoming of interest to scientists. Last month, the World Health Organization (WHO) listed "mu" as a "variant of interest" due to potential concerns it might be resistant to vaccines and treatments.

This comes as delta was solidified as the world's dominant strain and breakthrough cases in vaccinated adults increased. But WHO also stated it needs more evidence before determining a risk level. Even Dr. Anthony Fauci, President Joe Biden's chief medical adviser, said, "We don't consider it an immediate threat right now."

Of course, any new variant is something to be taken seriously. So, TPG spoke with Robert G. Lahita MD, Ph.D. ("Dr. Bob"), director of the Institute for Autoimmune and Rheumatic Disease at Saint Joseph Health and author of "Immunity Strong," about what travelers should know about mu.

For more TPG news delivered each morning to your inbox, sign up for our free daily newsletter.

What are the biggest concerns with the mu variant?

Dr. Bob: In a test tube, mu is one of the 33,000 RNA variations in the spike protein that may make it resistant to immunoglobulin [antibodies]. These mutations up-regulate and down-regulate the viral replication. So if the virus down-regulates via a mutation, it dies, it goes away. If it up-regulates -- what the mu has just done -- it becomes possibly more virulent. We simply don't know right now in the real world of patients what mu does.

Where is it currently circulating?

Dr. Bob: The new variant is present in South America, [countries] like Colombia, Ecuador and Peru. It's seen down there in about 39% of patients in Colombia and about 18% or 19% in Peru and Ecuador. It is not widely seen around the world. Only 0.1% of the world's population has the mu variant. The new variant has been seen in the United States, however, very sparsely.

How is it different from delta or other strains? Is it more contagious?

Dr. Bob: We know that it's not as contagious as the delta [variant]. But, there are so few cases, we simply don't know much else. I don't think it's time to sound the alarms because there's no evidence that mu is any more effective than the delta variant. The delta variant still remains the king of the heap.

How do vaccines hold up against the mu variant?

Dr. Bob: Again, in a test tube, it seems the mu variant might be somewhat resistant to standard immunoglobulins [anitbodies]. However, I'm told by everybody else that that may not be important because it looks like the Moderna, the Pfizer and the J&J vaccines protect against such variants as the mu.

How can I protect myself against the mu variant when traveling?

Dr. Bob: It goes back to the basics. Wash hands, wipe down surfaces and wear a mask. I would also recommend goggles around unmasked strangers [on] a plane, train or other crowded locations. The good news is these measures work amazingly.