(NEXSTAR) – Officials with the World Health Organization are urging for continued public health measures — including the wearing of masks for vaccinated individuals — as the SARS-CoV-2 delta variant spreads across the globe.

The variant, first identified in India, is the “most transmissible” of the COVID variants identified thus far, said WHO Director-General Tedros Adhanom Ghebreyesus at a media briefing on Friday.

“As some countries ease public health and social measures, we are starting to see increases in transmission around the world,” Tedros said of the variant, seen now in at least 85 countries. “More cases means more hospitalizations, further stretching health workers and health systems, which increases the risk of death.”

Tedros also blamed the increased transmission of the delta variant on the inequitable distribution of vaccines in poorer countries, warning that the same thing happened during the AIDS crisis and the 2009 swine flu pandemic.

Speaking of prevention measures specifically, Dr. Mariângela Simão, the WHO assistant director-general for drug access, vaccines, and pharmaceuticals, said at Friday’s briefing that continued health measures are still “super important” even among the vaccinated population. Specifically, Simão said people should be wearing masks “consistently,” practicing social distancing, staying in ventilated spaces, washing hands, and avoiding crowds.

“This still continues to be extremely important, even if you’re vaccinated, when you have a community transmission ongoing, which is the case of Latin America in general,” Simão said. “Now you have a high level of continuous community transmission. So people cannot feel safe just because they’ve had the two doses. They still need to protect themselves.”

Despite Friday’s advisories from WHO, the U.S. Centers for Disease Control and Prevention (CDC) has not yet changed its guidance for vaccinated individuals. The most recent update on June 17 says fully vaccinated Americans can resume most activities “without wearing a mask or physically distancing, except where required by federal, state, local, tribal, or territorial laws, rules, and regulations, including local business and workplace guidance.”

Meanwhile, during Friday’s WHO briefing, Maria Van Kerkhove, the WHO’s technical lead on COVID-19, pointed to the rising cases of the delta variant in Europe as an example of just how “fragile” the world’s current health situation is.

“There are a lot of events” that are causing numbers to spike in some European countries, Van Kerkhove said, citing sporting events, religious events, and even “backyard barbecues” as some of the catalysts.

Van Kerkhove further urged the public to “pull ourselves together” to drive down transmission rates.

“The delta variant, the virus, will continue to evolve. And right now our public health and social measures work, our vaccines work, our diagnostics work, our therapeutics work. But there may be a time where this virus evolves and these countermeasures don’t,” she said.

Van Kerkhove added that the delta variant is just one of four COVID variants of concern, along with seven other variants of interest and a “number of other alerts” about mutations that WHO is tracking.

The Associated Press contributed to this report.