CNN – A new and slightly changed version of the Delta coronavirus variant is spreading in a number of countries including the United Kingdom, United States and India, health officials say.
This strain, which has generated a significant amount of global media attention, is called B.1.617.2.1 or AY.1 — Delta Plus for short, and is a version of the Delta variant first detected in India in February.
It was first reported by Public Health England, a government health agency, on June 11. But the UK’s first few cases had been sequenced on April 26 — suggesting the variant may have been present and spreading by the spring.
The Indian government said it has submitted the variant to the Global Data System, and sent samples for genomic testing.
About 200 cases have been spotted in 11 countries. Health experts are investigating whether Delta Plus may be more transmissible than other strains like the Alpha or Delta variants — but it’s too early to say for sure what its effects may be.
Here’s what we know so far, and what questions are still unanswered.
How is Delta Plus different from the Delta variant?
All variants carry clusters of mutations. Delta Plus has an extra mutation called K417N, which distinguishes it from the regular Delta variant. This mutation affects the spike protein, the part of the virus that attaches to the cells it infects.
The K417N mutation isn’t entirely new — it has “arisen independently in several viral lineages,” said Francois Balloux, director of the University College London (UCL) Genetics Institute.
The mutation was seen in a strain found in Qatar in March 2020, and is also found in the Beta variant, which was first detected in South Africa last fall, he told the Science Media Centre on Wednesday.
“The mutation may contribute to immune escape, though its impact on transmissibility is not clear-cut,” he added.
All viruses mutate constantly. Some of those changes make viruses better at infecting cells, or better at replicating, while others have little effect or are even harmful to the virus.
To date, there have been about 160 strains of the coronavirus sequenced globally, said Balloux.
There are also “other Delta plus variants with other mutations,” said the Indian government on Wednesday, adding that AY.1 was just the most well known.
Maria Van Kerkhove, the World Health Organization’s technical lead on Covid-19, added that the team was “looking at these specific mutations and what these mean in terms of transmission, in terms of severity, and really importantly what these means in terms of our medical countermeasures.”
Meanwhile, the regular Delta variant, also known as the B.1.617.2 strain, has spread rapidly. It has been reported in dozens of countries, and is 40% to 60% more transmissible than the Alpha variant first identified in England, said the European Centre for Disease Prevention and Control (ECDC).