SAN FRANCISCO (KGO) -- The highly-contagious Delta variant is now the dominant strain in the U.S. From Missouri and Kentucky to Utah, much of the U.S. is in the midst of a summer COVID surge.
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"I would have thought that we would have had a little bit more of a break, that we would have continued the down slope more into August," said UCSF epidemiologist, Dr. George Rutherford about the current surges. He says the abbreviated break between surges happening in some parts of the country is easily explained.
"If we had more people vaccinated in those states or if we had more naturally acquire immunity in those states, we would be seeing less transmission. The less transmission we have the fewer variants will emerge."
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Dr. Rutherford says every three times a coronavirus reproduces, there's a chance it will mutate into a potentially more transmissible variant that may evade immunity.
"What we're seeing is a predominance of variants of concern," said Pavitra Roychoudhury, who works in the University of Washington virology lab. "We're watching these frequencies over time and we're obviously concerned about anything that seems to be rising rapidly because that seems to suggest that something is more transmissible."
Roychoudhury has been working on the genomic sequencing of SARS-CoV-2 since the start of the pandemic.
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The University published a study this week about the Epsilon variant - at one point known as the California variant - suggesting it could evade the vaccines. But, since the study began, the variant has become less prevalent.
"The epsilon variant a few months ago constituted almost 40% of samples at the highest levels and then it just gradually died down and it was over taken by the Alpha variant, and then more recently we've also seen the Gamma variant, and the Delta variant rising in frequency," said Roychoudhury.
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It's hard to know which variant will outcompete another, but Dr. Rutherford says that shouldn't matter. "If you get sick with Delta, or Epsilon or Alpha, or whatever it's all the same. You have the same chances of going into the hospital more or less, you have the same chances of having a severe case. But the trick is about not getting infected in the first place."
And the way to not get infected and prevent the virus from spreading is to get vaccinated.
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