The ‘Delta Plus’ variant has spread to nearly 30 countries, but low case numbers are a sign it won’t overtake Delta

The two variants are genetically similar, which is why they share the same Greek letter. But Delta Plus (also known as AY.1) has an extra mutation in the code for its spike protein, which helps the coronavirus gain entry to our cells.

India’s health ministry said last month that Delta Plus appears to spread more easily than Delta, and can potentially bind more easily to lung cells or resist antibody drugs. But an Indian genomics consortium suggested more recently that Delta’s sub-lineages probably aren’t more transmissible than Delta itself. As of July 23, India had recorded no more than 70 Delta Plus cases.

Both the US Centers for Disease Control and Prevention and World Health Organization still track Delta Plus as part of the Delta variant, meaning the cases aren’t separated. But data from Scripps Research’s Outbreak.info tracker suggests that just 430 Delta Plus cases have been detected worldwide.

South Korea announced Tuesday that it had recorded its first two cases of Delta Plus. The nation is battling its heaviest surge of infections yet, most likely driven by the original Delta strain.