Indian Coronavirus variant has reached the US-- Background information

Coronavirus variant that first appeared in India arrives in the US. Here's what to know. Experts say the India variant probably will not cause great harm in the U.S. because of high vaccination rates, but they are watching it. Elizabeth Weise and Karen Weintraub USA TODAY

The B.1.617 coronavirus variant devastating India right now has arrived in the United States. Experts say it's not likely to cause much harm here because of high vaccination rates and because the health care system is not under stress. But with a virus that has defied expectations and the variant infecting hundreds of thousands of Indians every day, researchers are keeping an eye on it.

Here's what you need to know about the coronavirus variant that originated in India:

It first appeared in India, where it is believed to have contributed to that nation's devastating second wave of COVID-19. It was dubbed a "variant of concern" by the World Health Organization last week because of worries it might be more contagious and may more easily evade existing vaccines.

There are several sublineages of the variant, including B.1.617.1 and B.1.617.2. 

It's sometimes called a "double mutant" because it has double the number of mutations as some earlier variants of the SARS-CoV-2 virus, which causes COVID-19. The concern at firstwas that might make it doubly dangerous. "The good news is, this doesn't appear to be the case. Having both mutations was no worse than having just one," said Dr. Charles Chiu, a professor and expert in viral genomics at the University of California, San Francisco. 

The U.S. is one of 49 counties where the variant has spread, but so far it is at low levels here. As of May 8, the B.1.617 variant made up 3% of all COVID-19 cases in the United States, according to the Centers for Disease Control and Prevention. It does seem to out-compete the B.1.1.7 variant, first seen in the U.K., at least in India, said Dr. Krutika Kuppalli, a fellow of the Infectious Diseases Society of America and an infectious disease specialist at the Medical University of South Carolina. B.1.1.7 now accounts for 72% of COVID-19 infections in the U.S., according to CDC data released Wednesday. ...

Do the U.S. vaccines work against the variant?

They appear to be working. Blood samples from previously infected or vaccinated people were only one-seventh as effective against the B.1.617 variant as against the original virus, but that is believed to be enough to be protective, particularly against severe disease and hospitalization, said Mehul Suthar, a virologist at Emory University who co-wrote a paper on the variant published May 10 but not yet peer-reviewed.

"Despite this reduction, all vaccine blood samples and nearly 80% of blood samples from individuals that had been previously infected still maintained the ability to block this Indian variant," Suthar said.  ...

ASLO SEE: Additional background---How worrying is the variant? --AP