The head of the World Health Organization said the COVID-19 delta variant is “the most transmissible of the variants identified so far,” and warned it is now spreading in at least 85 countries.

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

Tedros said that new variants are expected and will continue to be reported, but stressed the emergence of variants can be prevented by preventing COVID-19 transmission.

The WHO chief also criticized rich countries for declining to immediately share shots with the developing world, saying the global community was failing in supplying enough vaccines to poor countries.

Meanwhile, Reuters says the WHO has received submissions from at least three vaccine makers for emergency approval for additional vaccines and expects to approve at least one or two of them in the next month or two.

This is according to WHO assistant director-general Mariangela Simao, who did not specify which new vaccines were being considered. 

The WHO has so far given emergency approval to vaccines from Pfizer, AstraZeneca, Johnson & Johnson, Moderna, Sinopharm and Sinovac.

Any new vaccines gaining approval can then be supplied worldwide through the COVAX Facility program.