Coronavirus latest: Cases on the rise in 3 US states

The World Health Organization announced Monday that 156 economies are committed to or eligible to receive vaccines through the organization’s COVAX facility.

The nations, which do not include the U.S., China and Russia, represent 64% of the world’s population. WHO leaders said their target is to issue 2 billion vaccine doses through COVAX by the end of 2021, which would vaccinate around 25.6% of the world's 7.8 billion population, under a one-dose regimen.

"There's no guarantee that any vaccine in development will work," WHO Director-General Dr. Tedros Adhanom Ghebreyesus said in Geneva, but he added, "we must move heaven and earth" to ensure equitable access to diagnostics, therapeutics and vaccines.

Higher income governments are committed to provide an upfront payment to reserve doses by Oct. 9, 2020, WHO said.

The allocation of vaccines, once licensed and approved, will be guided by an Allocation Framework released Monday by WHO following the principle of fair and equitable access, ensuring no participating economy will be left behind.

"The race for vaccines is a collaboration not a contest," Tedros said, "It's in every country's best interest, we sink or we swim together."

ABC News' Christine Theodorou contributed to this report.

The U.S. Centers for Disease Control and Prevention issued and later removed updated guidance on its website to address growing evidence of limited airborne transmission of the virus that caused COVID-19.

It’s already known that the novel coronavirus is most commonly transmitted "through respiratory droplets or small particles, such as those in aerosols, produced when an infected person coughs, sneezes, sings, talks, or breathes."

On Friday, the CDC also included that "There is growing evidence that droplets and airborne particles can remain suspended in the air and be breathed in by others, and travel distances beyond 6 feet (for example, during choir practice, in restaurants, or in fitness classes)," noting that "In general, indoor environments without good ventilation increase this risk."

But on Monday morning, the updated information on airborne transmission was removed from the site and in its place, the agency explained that posting the new information was done in error.

"A draft version of proposed changes to these recommendations was posted in error to the agency's official website. CDC is currently updating its recommendations regarding airborne transmission of SARS-CoV-2 (the virus that causes COVID-19). Once this process has been completed, the update language will be posted."

The World Health Organization acknowledged in July that the novel coronavirus could spread through the air, after hundreds of scientists called for the global health arm of the United Nations to recognize the risk of airborne transmission.

ABC News' Eric Strauss and Sony Salzman contributed to this report.

Eastern Michigan University said it will soon begin testing wastewater on campus for signs of COVID-19 and other infectious diseases.

As part of its return-to-campus plan, the public research university is partnering with Michigan-based firm Aquasight to track the presence of the novel coronavirus in wastewater flowing from residence halls and apartment complexes on the school's campus in Ypsilanti, west of Detroit.

Tests have shown that wastewater contains infectious biomarkers that can signal the growth or reduction of the virus in a community or around a college campus, according to Eastern Michigan University President James Smith.

"This monitoring process, while not diagnostic, may provide early detection of asymptomatic cases," Smith said in a statement Friday. "The results of the tests will help us pinpoint any concerning trends and expand individual testing among specific populations as necessary."

Other schools, including the University of Arizona and Utah State University, are reportedly doing similar testing.

More than 200 asylum seekers who recently resettled at a new temporary camp on the Greek island of Lesbos, after the old one had burned down, have tested positive for COVID-19, according to Greek government spokesmen Stelios Petsas.

During a regular press briefing Monday, Petsas said that all 7,064 individuals who were admitted to the new Kara Tepe camp, near the island's capital Mytilene, had been tested for COVID-19 and that 243 of them were found to be infected.

The average age of those who tested positive was 24, and most didn't have any symptoms, according to Petsas.

Another 160 people who had come into contact with the migrants, mostly police officers and administrative staff at the camp, were also tested for the virus but all had negative results, Petsas said.

The new facility is not far from the remains of the Moria camp, where fires forced some 12,000 migrants to flee last week and seek shelter. Greek police believe the blazes were set deliberately by a small group of migrants angered by a lockdown imposed after a COVID-19 outbreak at the overcrowded camp. Six people, all Afghan nationals, have been arrested on suspicion of arson.