Researchers in Arizona analyzed the genetic makeup of more than 100 samples of the new coronavirusfrom patients with COVID-19 and believe they have found one dominant strain of the virus circulating in Arizona.

The strain seems to be connected to strains from Europe and is thought to have established itself in Arizona in early March, according to Michael Worobey, head of the University of Arizona's Department of Ecology and Evolutionary Biology.

It's unclear whether the virus came to Arizona directly from Europe, or through another state such as Utah or Washington, which also have cases related to the same European strain of the virus.

This dominant strain accounts for less than 50% of the currently analyzed samples, and just because it is the dominant strain does not mean it is more infectious than others.

"Functionally, we think all of these viruses have had the same ability to infect people. So when you see a dominant lineage, it's just telling you that by chance, one got in early and got a foothold," Worobey said.

Looking at the genetic trail of bread crumbs from each case shows that the initial case of COVID-19 in Arizona in January does not seem to have caused any sort of outbreak, according to David Engelthaler, co-director of the Translational Genomics Research Institute’s Pathogen and Microbiome Division.

"We're lucky we didn't follow the same situation as Washington where we had a lot of underlying disease, because then once you find it, you start finding it everywhere," Engelthaler said. "It looks like we had a bit of a break between that very first case in January and then the subsequent cases."

TGen has teamed up with the UA and Northern Arizona University to track different genetic strains of the new coronavirus. Together, the newly formed Arizona COVID-19 Genomics Union hopes to use big data analysis and genetic mapping to give Arizona health care providers and public policy makers an edge in fighting the growing pandemic.

The 100 virussamples that helped spot the dominant strain were genetically mapped through supercomputing machines that show researchers every part of the virus's genetic code.

The data produced from the mapping can offer researchers other clues about the pandemic, such as which areas of the state have the most cases and the highest rates of spread, how cases are related to each other, how fast the virus is mutating and how fast the rate of cases is doubling.

"So we're going to be able to look back and say, 'OK, over this last while in March when things were growing without much social distancing, how fast is this epidemic moving?'" Worobey said.

"And after the stay-at-home order was put out by the governor, then we're going to be able to see, what's the effect?" he said. "We'll be able to scientifically test that and hopefully show some nice evidence that these measures that are so painful are actually having the effect that you would want."

Researchers weren't yet able to say how fast cases of COVID-19 were doubling but said they expect to publicly share that information and analysis in a few days. They were also not yet able to give a full picture of where hot spots for transmission have developed and where the virus is spreading, but they believe a fuller picture could emerge in the coming weeks.

So far, the data show that the virus is mutating relatively slowly, according to Paul Keim, executive director of NAU's Pathogen and Microbiome Institute. The new coronavirus has 30,000 base pairs of nucleotides. Those are the building blocks of genetic material and are counted in "base pairs" because each rung on the ladder-like genome structure is made of a pair of nucleotides.

Of the 30,000 base pairs, Keim said only 10 or 12 have mutated in the past few months.

"We don't think that's enough to matter functionally for how the virus does its job or ... for how our immune system sees it," Keim said. "All of these are going to look the same to our immune system at this point."

This is critical information for the development of vaccines, treatments and testing because all of them target specific parts of the virus's genetic code. If a key part of the virus mutates, it could render vaccines currently under development ineffective, so Keim said it's important to track changes so that researchers can stay ahead of the virus.

He estimated that it would be a few years before the virus mutated enough to be seen differently by the immune system.

"This is one of the reasons it's important to go as fast as we can with the science now because we're in a sweet spot now where if we do develop a vaccine, it's likely to work across every lineage in the world, but if that takes too long, that's going to become more challenging," he said.

TGen is racing to generate genetic maps for more than 200 new coronavirus samples by the end of the week, and Engenthaler said they hope to start processing 100 to 200 samples a day.

A good vaccine distributed quickly worldwide could still drive the new coronavirus into extinction, but Keim said the possibility of doing so is looking less and less likely. Instead, he said, it's more likely that the new coronavirus will establish itself as a seasonal virus like influenza that requires attention year to year.

Even if the number of cases starts to go down, he said he expects to see smaller outbreaks of the virus after the initial peak.

"I don't think the talk of reaching a peak should allow people to think we've got a couple more weeks of being careful and then it's back to normal," he said.

With continued outbreaks being a concern, vaccines a long way off and no guarantee of lifelong immunity, Keim expects that people will become a lot more conscientious about good hygiene practices, more willing to stay home when they are sick, and more cautious.

"These behavioral changes that we're experiencing now are pretty extreme, but we're not ever going to go back to normal, in my opinion," he said. "At least not in this generation."

Amanda Morris covers all things bioscience, which includes health care, technology, new research and the environment. Send her tips, story ideas, or dog memes at amorris@gannett.com and follow her on Twitter @amandamomorris for the latest bioscience updates.

Independent coverage of bioscience in Arizona is supported by a grant from the Flinn Foundation.

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