First detected in India in late 2020, the COVID-19 variant known as Delta now accounts for almost every infection globally, the World Health Organization stated on Tuesday.

The coronavirus variant is known for its transmissibility. Scientists in the U.K. have stated that the Delta variant is between 40% and 60% more transmittable than the Alpha variant, which was first recognized in the U.K. 

While cases continue to surge throughout Europe, WHO technical lead on COVID-19 Maria Van Kerkhove said infections within the continent were responsible for around 60% of the more than 3 million new cases reported globally last week.

Vaccinated individuals generally have mild symptoms if they contract the Delta variant.

“Where Delta is present, Delta takes over,” Van Kerhove said. “[It] is really the dominant one."

The Delta variant also can cause symptoms two to three days sooner than the original coronavirus, especially for younger people. This is more troublesome for the immune system as it is given less time to create a defense.

Dr. Inci Yildirim, a Yale Medicine pediatric infectious diseases specialist and a vaccinologist, says that  “a study from the United Kingdom showed that children and adults under 50 were 2.5 times more likely to become infected with Delta.

"As older age groups get vaccinated, those who are younger and unvaccinated will be at higher risk of getting COVID-19 with any variant, but Delta seems to be impacting younger age groups more than previous variants.”

The Pfizer COVID-19 vaccine was approved by the FDA on Oct. 29 for children in the 5-11 age group, nearly a year after it was made available for adults.