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Doctors explain why mutated strain of coronavirus that is dominant in Houston is more contagious but not more deadly

HOUSTON – As research leads to a better understanding of COVID-19′s effect on the human body, doctors in the Texas Medical Center Monday offered insight into a strain of the coronavirus that seems to be more contagious – a strain considered the main one wreaking havoc in Houston.

New research published last week, concluded a mutated strain is more infectious, but local doctors said the strain itself isn’t new to Houston and should not heighten concerns.

“It’s actually been here for three to four months already,” said Dr. Joseph Petrosino, chairman, Department of Molecular Virology and Microbiology, Baylor College of Medicine. “Probably appeared in February or March as the virus was making its way out of China and into Europe,” Petrosino continued.

Still, the very mention of words such as “mutation,” and talk about a coronavirus strain that seems stronger, is more than enough to fray already tattered nerves.

To that end, local researchers say there’s no need to heighten one’s sense of concern.

“This is really one of the things about the SARS-COV-2 virus that causes COVID-19 that people around the world have studied for months trying to figure out what the implications are for – why it’s so dominant,” said Dr. S. Wesley Long, medical director, diagnostic microbiology, Houston Methodist Hospital.

Doctors: mutated strain in Houston since March

Doctors in the Texas Medical Center have gathered data from local COVID-19 patients since the area’s first positive cases came to light in March. Even then, researchers noticed various strains of the virus – something they insist is normal.

“It does seem that this mutation provides a competitive advantage compared to the previous virus. However, there’s been no increase in disease severity associated with it at this point in time. No increase in deaths with this particular strain of the virus,” Petrosino said.

Other local experts underscored that latter point.

“There’s no connection to disease severity and it’s a mutation that’s been dominant, circulating Houston and the U.S.,” Long said.

Long served as one of the lead authors in a preliminary study Houston Methodist published in May. That study concluded most strains in the Houston area are mutations from Asia and Europe.

A preliminary report means the research is awaiting peer review.

A mutated strain? What’s that?

Living organisms mutate. That means they have the ability to permanently change their genetic makeup.

The study published last week focused on a mutations that appear to stabilize the spike proteins on the outer surface of the virus.

Perhaps you’ve seen illustrations of how a strain of COVID-19 looks — a sphere-shaped organism with cone-like spikes around its circumference.

Focus on those spikes.

“With this mutation, the spikes are stronger. They persist longer on the surface of the virus. So, there’s more of them on the virus, according to researchers at Scripps,” Petrosino said.

Translation: the study found the stronger spike proteins allowed the virus to more easily infect human cells.

“With that, they inferred the strain is more easily transmitted from person-to-person,” Petrosino explained.

The inference, experts said, is worthy of more research to determine, for sure, whether the mutation provides an advantage for transmission.

“In this model system it seems to slightly be more infections, but that’s really all there is,” Long said, reinforcing his point that the mutated strain does not equate to a more severe – or deadlier form.

What should you do?

Doctors suggest you continue with the health guidelines laid out for months, including washing your hands frequently, wearing masks, social distancing and frequently sanitizing surfaces. Beyond those measures, health officials say there is nothing more you can do to protect yourself from the mutated strain of the virus.