The World Health Organization (WHO) named the delta variant coronavirus as the "most contagious" one in a report on Saturday.

Iran PressEurope: The head of the World Health Organization said the COVID-19 delta variant, first seen in India, is "the most transmissible of the variants identified so far," and warned it is now spreading in at least 85 countries.

At a press briefing on Friday, WHO director-general Tedros Adhanom Ghebreyesus said the lack of vaccines in poor countries was exacerbating the delta variant's transmission.

He described a recent meeting he attended of an advisory group established to allocate vaccines.

"They were disappointed because there is no vaccine to allocate," he said, criticizing rich countries for declining to immediately share shots with the developing world. "If there is no vaccine, what do you share?"

Tedros said the global community was failing and risked repeating the mistakes made during the AIDS crisis decades ago and during the 2009 swine flu pandemic — when vaccines only arrived in poor countries after the outbreak ended.

The B.1.1.7 virus, first identified in the UK, is called alpha; the B.1.351 virus, first seen in South Africa, is called beta, P.1 is named Gamma, and B.1.617.2 which was identified in India is named Delta.