Iowa will roll back several COVID-19 restrictions starting Sunday, including a requirement that masks be worn indoors.

Gov. Kim Reynolds issued a new proclamation Friday that does not include any requirements around facial coverings.

Under a previous proclamation, set to expire Saturday, masks were required in indoor public spaces when social distancing for at least 15 minutes was not possible.

The new proclamation also does not impose any restrictions on public gatherings, which previously had to follow social distancing and other guidelines.

Regarding gatherings, the new proclamation states, "I strongly encourage that all businesses or other employers remaining open with in-person operations take reasonable measures under the circumstances of each establishment to ensure the health of employees, patrons and members of the public, including social distancing practices, increased hygiene practices and other public health measures to reduce the risk of transmission of COVID-19 consistent with guidance issued by the Iowa Department of Public Health."

The governor has been loosening restrictions in recent weeks around public gatherings for sports, restaurants and bars as new COVID-19 cases and hospitalizations have trended downward from peaks in November.

Iowa, which initially issued its mask requirement in mid-November, will be one of 15 states that doesn't have a statewide mask mandate, according to a tally by Masks4All.

Delta will offer vaccinations to Georgia employees who are 65 and older starting on Monday, a company spokesperson confirmed to ABC News.

A health care provider will administer the vaccines in a section of the Hartsfield-Jackson Atlanta International Airport (Concourse C) and space at the Delta Flight Museum from Feb. 8 to Feb. 14. Delta's headquarters are located in Atlanta.

Delta CEO Ed Bastian said in a memo last week that 690 Delta employees had received at least one vaccination shot.

"We continue to work with federal and state authorities to prioritize immunizations for frontline Delta people," Bastian wrote in the memo. "While healthcare workers and our most vulnerable are already getting their shots, I strongly encourage each of you to get vaccinated when your time comes."

ABC News' Mina Kaji contributed to this report.

The number of COVID-19 vaccinations around the world now surpasses infections, Dr. Tedros Adhanom Ghebreyesus, director general of the World Health Organization, said during a Friday news briefing. "In one sense, that is good news and a remarkable achievement in such a short time frame."

On the other hand, he noted, those vaccinations have not been distributed equally.

"More than three quarters of those vaccinations are in just 10 countries that account for almost 60% of global GDP," Tedros said. "Almost 130 countries with 2.5 billion people [have] yet to administer a single dose. Some countries have already vaccinated large proportions of their population who are at lower risk of severe disease or death.”

Tedros urged drug companies to share their technology and data to ensure more equitable access.

"The longer it takes to vaccinate those most at risk everywhere, the more opportunity we give the virus to mutate and evade vaccines," Tedros said. "Unless we suppress the virus everywhere we could end up back at square one."

ABC News' Kirit Radia contributed to this report.

People with certain chronic conditions will be eligible for COVID-19 vaccinations on Feb. 15, Gov. Andrew Cuomo announced during a Friday press conference. Underlying conditions are a key risk factor for severe COVID-19 illness and death. Cuomo posted the full list of conditions on Twitter Friday afternoon, which included people with cancer, heart conditions, chronic kidney disease, severe obesity and those who are pregnant.

Dr. Stephen Hoge, president of American biotechnolgy company Moderna, said he's hopeful that vaccines can help the U.S. population achieve herd immunity against the novel coronavirus by mid-year.

"It really depends what you think herd immunity needs to be. But if you assume 50 to 70% of the population, then we're working hard ourselves and the other manufacturers to make sure that's a possibility really in the late spring, early summer," Hoge told ABC News chief anchor George Stephanopoulos in an interview Monday on "Good Morning America."

"It's ultimately going to depend upon the delivery of those vaccines, and so that's something that the states and the health care providers in this country are ultimately leading the way on as well as Americans deciding they want to receive that vaccine," he added. But we're optimistic that by the middle of the year, we'll be able to achieve those sorts of numbers."

Moderna is ramping up production of its COVID-19 vaccine and is working to clear any "bottlenecks" in the supply chain, according to Hoge.

"At this point, a lot of the logistical bottlenecks that we're running into are problems we can solve on our own," he noted. "We're in good shape."

Hoge, who was a resident physician in New York City, said data currently shows that existing vaccines are still effective against all emerging strains of the virus. But the variant first identified in South Africa "is of some concern because it looks like it could hide from the vaccine a little better than others," he said.

"So our approach in Moderna is going to be to develop a booster vaccine so that if the South African variant or any other variant becomes a concern, we'll be able to offer a way to identify that, prevent it from hiding from the vaccine," he said.