Doctors say mu COVID variant is in Houston, but delta variant remains most concerning

HOUSTON, Texas (KTRK) — Mu is the latest COVID-19 variant labeled as a “variant of interest” by the World Health Organization. Dr. Wesley Long, director of diagnostic microbiology at Houston Methodist Hospital, said they have seen patients infected with the mu variant, however, the delta variant remains dominant.

“We’ve seen a few cases of the mu variant really starting back in May. We’ve seen less than 50 cases total and that’s in this fourth wave of delta where we’ve seen many thousands of cases of the delta variant. At the present, we’re seeing, 99% of all of the COVID, we’re seeing is delta and it’s been that way for several weeks,” explained Long.

She said the mu variant was first reported in Central America.

“The mu variant was described in Central America back in December to January of the past year. That’s where it was first described and first found,” said Long.

Health experts are keeping an eye on the mu variant as some lab tests show it may be able to evade the vaccine. However, those studies are preliminary and doctors say more research will need to be done to determine if the variant is really able to evade vaccines in humans.

Overall, Long said the delta variant remains more concerning.

“If the (mu) variant is here and we’re detecting it at a low level, that means there are people in the community that have it. It is capable of being spread and we are not seeing it start to grow exponentially. It would tend to suggest that the dominant variant that we have right now, which is delta, is outcompeting mu and lambda and all of those other variants,” explained Long.

Dr. Peter Hotez with Baylor College of Medicine about the mu variant. He explains it is a potential concern.

“I would say, you know, it is a potential concern downstream because it does look like it has some features that could make it partially resistant to vaccines and thwart some of the virus-neutralizing antibodies,” said Hotez.

Hotez explains there are some similarities between the mu variant and the South African variant, which is partially resistant to the vaccines.

“The concern is that the mu has an amino acid substitution in the 501 and 484 positions and those are the same substations that the South African variant has in the same place which is partially resistant to the vaccines,” said Hotez. “So I hope mu doesn’t get up too much more, but if we continue to boost, we should be OK even with that,”

At this point, Hotez agrees mu is a minor player and the delta variant is what remains the most concerning.