WHO director predicts 100 million additional coronavirus cases worldwide

"At the current trajectory, we could pass 300 million cases early next year," he said during a media briefing. "But we can change that. We are all in this together, but the world is not acting like it."

The number of recorded covid-19 cases had reached 200 million last week, just six months after the world passed 100 million cases, Tedros noted, "and we know that the real number of cases is much higher."

At the briefing, WHO officials emphasized that more research was being done on treatment for covid-19 in an unprecedented multicountry trial called Solidarity Plus, which will look at the effectiveness of three new drugs in 52 countries.

Officials also said the spread of virulent variants such as delta would change assumptions about herd immunity and vaccination targets.

"There's no specific number or magic number that needs to be achieved. Its really related to how transmissible the virus is," said Katherine O'Brien, director of the WHO's immunization department.

"What's been happening with coronavirus . . . is that as variants are emerging and are more transmissible, it does mean that a higher fraction of people need to be vaccinated to likely achieve some level of herd immunity," O'Brien said.

With the delta variant continuing to drive up cases in the United States, some state and local officials weighed mask mandates as President Joe Biden met at the White House Wednesday with business leaders who have actively encouraged vaccinations among their workers.

Oregon Gov. Kate Brown, D, is expected Wednesday to put in place a statewide indoor mask mandate and to require vaccines for state employees, citing concerns over growing coronavirus cases due to the more transmissible delta variant.

The indoor mask mandate will make Oregon the third state - following Louisiana and Hawaii - to apply the measures to both vaccinated and unvaccinated people, as bans on mask and vaccine mandates play out in a number of Republican-run states such as Texas and Florida. Washington, D.C., also requires people to wear masks inside public places, regardless of vaccination status. Nevada Gov. Steve Sisolak, D, last month mandated that face coverings be worn indoors in public settings in counties with "substantial or high transmission."

"There are two keys to saving lives," Brown said in a statement. "Vaccination is the best way to protect yourself and your family against severe illness, hospitalization, and death. And, by wearing masks, all of us - vaccinated and unvaccinated - can help ensure that a hospital bed staffed by health professionals is available for our loved ones in their time of need."

Brown also said stricter measures would ensure the return of children to classrooms with "minimal disruptions in a few weeks" and avoid a repeat of the "darkest days of our winter surge."

Her decision comes as schools and political leaders battle over masks elsewhere. Florida's second-largest school system is now threatening legal action to challenge the ban on mask mandates by Gov. Ron DeSantis, R, and voted Tuesday to keep its own requirements in place for students and staff.

The Broward County School Board - which voted 8 to 1 on Tuesday to uphold its mask mandate despite DeSantis's move to curb such restrictions and subsequent threat to stop paying superintendents and school board members who defy his orders - said in an evening news conference that it told its legal counsel to prepare a challenge.

"We feel that we took an oath to protect and serve the people of Broward County," said Rosalind Osgood, chair of the school board. "Our decision today to make masks mandatory is our way of doing that."

Political tensions with the federal government are heating up, too: The Biden administration is looking into whether it can direct unused stimulus funds to support educators in Florida who may defy the governor's order against mask mandates in schools.

DeSantis recently threatened "financial consequences" for district-level officials who implement mask mandates despite his order banning them. Florida has become a national hot spot for coronavirus cases. The federal government has sent hundreds of ventilators to help Florida respond to the crisis, NBC News reported, citing officials at the Department of Health and Human Services.

White House press secretary Jen Psaki described Biden's meeting as a "way of lifting up private-sector companies who are taking steps - through carrots and sticks, through incentives, and through mandates in some cases."

The session included leaders of United Airlines, Kaiser Permanente, Howard University and DESA Inc., a professional services firm based in Columbia, S.C. Administration officials said they hoped to spur other companies to follow their lead in prodding employees to get vaccinated.

"I wouldn't say it was meant to be a decision meeting, as much as a discussion about best practices," Psaki said. "And hopefully they can be a model for others."

Asked if Biden believes all companies should impose vaccine mandates on their workers, Psaki demurred.

"The president's position is that every company should take a look at how to protect their workforces, and there are going to be different carrots and sticks that can be used by different private sector entities," she said.

Also in D.C., Mayor Muriel Bowser, D, announced Tuesday that all city employees and contractors will be required to be vaccinated or undergo weekly testing for the coronavirus, with vaccination required for new employees.

And the nation's top infectious-disease expert, Anthony Fauci, threw his weight behind vaccine mandates for teachers.

"We are in a critical situation now," Fauci said on MSNBC's "Morning Joe" on Tuesday when asked if teachers should be required to get vaccinated against the coronavirus. Acknowledging the polarization, Fauci replied, "I'm going to upset some people on this, but I think we should."

Some schools are already following his advice. The San Francisco Unified School District announced Tuesday it would require vaccinations for all its approximately 10,000 staff, starting Sept. 7. Employees who are unvaccinated will be required to get tested weekly for the virus.

"Given that we are in the midst of rising cases and new variants in our community, a vaccine requirement is a necessary step to keeping our students, staff and families safe," Superintendent Vincent Matthews said in a statement.

But about half of parents nationally are holding off on coronavirus vaccinations for their children, taking a wait-and-see attitude or, for many, opposing the shots outright, according to a Kaiser Family Foundation poll released Wednesday.

There was also significant opposition to schools mandating the vaccines for children ages 12 to 17 - a group now eligible for the shots under emergency Food and Drug Administration authorization. Nearly 6 in 10 parents oppose a vaccine mandate to attend in-person classes, the poll found.