Oregon is the first state to bring back outdoor mask mandates for both vaccinated and unvaccinated people amid a sharp new rise in cases

• Oregon will require masks in most outdoor settings from Friday, Gov. Kate Brown said Tuesday.
• The rule will apply to most people aged 5 or over, and to both vaccinated and unvaccinated people.
• The measure comes as some outdoor events were linked to COVID-19 clusters, a state official said.

Oregon is becoming the first state to bring back statewide outdoor masking requirements as the Delta variant drives a sharp new surge in cases.

Masks will be required in most outdoor settings "where physical distancing is not possible, regardless of vaccination status," Gov. Kate Brown said on Tuesday.

The requirements, which come into effect on Friday, will apply to most people over the age of five, the governor's office said in a press release.

People will not need to wear masks in the cases of "fleeting" encounters, such as walking the dog in the morning or crossing paths on a hiking trail, Brown said.

Masking is also "strongly recommended," but not mandatory, for outdoor gatherings in private residences, but will not apply to homeless people, Brown said.

The measure is aimed at curbing the spread of the Delta variant, which is "throwing our state into a level of crisis we have not yet seen," Brown said.

The state, which has fully vaccinated about 57% of its population, has seen a sharp increase in cases, according to figures from Our World in Data and the Centers for Disease Control and Prevention.

Real-world data suggests that while vaccinated people can still catch and transmit the coronavirus, full vaccination is highly protective against severe infection, hospitalization, and death from the coronavirus, even against the Delta variant.

Oregon reported a record 1,000 COVID-19-related hospitalizations on Tuesday alone, Brown said.

CDC guidelines stay that masks are "in general" not needed outdoors, regardless of vaccination status, but people can "consider" wearing masks in crowded settings where rates of COVID-19 are high.

But Dr. Dean Sidelinger, Oregon's state health officer, said in a Tuesday statement that recent instances of cases clustering around outdoor events have prompted concern. Sidelinger did not give specifics on those events.

Earlier this month, authorities in Cornwall, England, said they found 4700 new COVID-19 cases they think could be linked to an outdoor surf-and-music festival that took place ten days prior.

Last month, at least 964 cases of COVID-19 were also linked to an outdoor music festival in Utrecht, The Netherlands.