The Delta variant of COVID-19, by far the most contagious strain during the entire pandemic, has different and more dangerous symptoms than the original virus, doctors are now warning.
The strain, first detected in India in December 2020, now makes up 90 percent of new cases in the United Kingdom and 10 percent of new cases in the United States.
Doctors in China told state-run television that their patients who have the Delta strain, known as B.1.617.2, are becoming sicker and their conditions are worsening at a faster rate, according to The New York Times.
Around 12 percent of Delta variant patients become critically or severely ill within three to four days after exhibiting symptoms - a substantial increase of the two to three percent seen with the original virus, according to The New York Times.
Symptoms also differ between the Delta variant and the original COVID virus, with stomach pain, loss of appetite, vomiting, nausea, joint pain, and hearing loss reported in those infected with B.1.617.2.
Dr. Scott Gottlieb, the former commissioner of the Food and Drug Administration, said the Delta strain could be the dominant source of new infections in the United States, possibly leading to outbreaks in some regions in the fall.
"Right now, in the United States, it's about 10 percent of infections," Gottlieb said on CBS-TV's "Face the Nation" on Sunday, June 13. "It's doubling every two weeks.
"That doesn't mean that we're going to see a sharp uptick in infections, but it does mean that this is going to take over. And I think the risk is really to the fall that this could spike a new epidemic heading into the fall."
Data suggests that those who have been fully vaccinated remain protected from the Delta variant, but more than one-third of Americans have not been fully vaccinated, and most children are not eligible to receive vaccines.
In some areas of the United States where 50 percent or less of residents have been fully vaccinated, the Delta variant is expected to take root, leading to another spike in those regions.
Neil Ferguson, an epidemiologist in the United Kingdom, said last week that the Delta variant is about 60 percent more transmissible than the original UK strain, known as B.1.1.7.
A new Gallup poll shows 76 percent of Americans say they've either been vaccinated or plan to be - a number that's held steady the last three months.
Sixty percent of US adults reported they have been fully vaccinated against COVID in the Gallup survey, conducted May 18-23.
Among those not planning to be vaccinated, 78 percent said they are unlikely to reconsider their plans, including 51 percent who say they are "not likely at all" to change their mind and get vaccinated.
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