The Centers for Disease Control and Prevention issued a federal transportation mask mandate Friday night which will be effective starting Feb. 1.

The mandate states that people traveling within or out of the United States must wear face masks while on conveyances and at transportation hubs to prevent the spread of COVID-19.

This includes airplanes, ships, ferries, trains, subways, buses, taxis and ride-shares, as well as subway stations, airports and other transportation hubs.

Drivers, conductors, and other workers involved in the operation of conveyances must also wear masks at all times, the CDC says.

"Conveyance operators must also require all persons onboard to wear masks when boarding, disembarking, and for the duration of travel," the mandate states. "Operators of transportation hubs must require all persons to wear a mask when entering or on the premises of a transportation hub."

There have been more COVID-19 cases reported globally in the past two weeks than during the first six months of the pandemic, according to the World Health Organization.

Almost exactly a year ago, there were fewer than 100 confirmed cases of the virus outside of China, WHO Director-General Dr. Tedros Adhanom Ghebreyesus noted during a media briefing Friday. This week, the number of reported cases globally surpassed 100 million.

"Now, vaccines are giving us another window of opportunity to bring the pandemic under control. We must not squander it," Tedros said.

At the same time, Tedros warned that vaccine hoarding will be a "catastrophic moral failing" that will ultimately "keep the pandemic burning" and hinder economic recovery.

His comments come after the European Union publicly fought with AstraZeneca this week over how many doses it can expect of the drugmaker's COVID-19 vaccine. After regulators approved the vaccine Friday, the EU enacted an export restriction on doses produced in the bloc. WHO officials called the move "concerning" and part of a "worrying trend."

"Vaccine nationalism might serve short-term political goals, but it's ultimately short-sighted and self-defeating. We will not end the pandemic anywhere until we end it everywhere," Tedros said. "My message to governments is to vaccinate your health workers and older people, and share excess doses with COVAX, so other countries can do the same."

ABC News' Kirit Radia contributed to this report.

The CDC is extending its moratorium on housing evictions through March 31, citing the health threat it poses.

The order had been set to expire on Jan. 31.

“Keeping people in their homes and out of congregate settings -- like shelters -- is a key step in helping to stop the spread of COVID-19,” the CDC said in a statement.

ABC News’ Anne Flaherty contributed to this report.

At Friday’s White House press briefing, Dr. Anthony Fauci said the United Kingdom variant will likely become more “dominant” in the U.S. toward the end of March or early April.

There are 379 confirmed cases across 29 states of the B117 strain of the coronavirus, according to CDC director Dr. Rochelle Walensky.

Fauci indicated that the evolving nature of the virus is something the medical community will have to continue dealing with going forward.

“Even though the long-range effect in the sense of severe disease is still handled reasonably well by the vaccines, this is a wake-up call to all of us, that we will be dealing, as the virus uses its devices to evade pressure, particularly immunological pressure, that we will continue to see the evolution of mutants,” he said.

Fauci also indicated that the fight to contain the new variants will impact the vaccine response.

“We, as a government, the companies, all of us that are in this together, will have to be nimble to be able to just adjust readily to make versions of the vaccine that actually are specifically directed towards whatever mutation is actually prevalent at any given time,” he said.

ABC News’ Matthew Vann contributed to this report.

COVID-19 cases and deaths are surging across Africa as new, more contagious variants of the novel coronavirus spread to additional countries, the World Health Organization warned Thursday.

"The variant which was first detected in South Africa has spread quickly beyond Africa and so what’s keeping me awake at night right now is that it’s very likely circulating in a number of African countries," Dr. Matshidiso Moeti, the WHO's regional director for Africa, said in a statement.

Diagnosed COVID-19 infections increased by 50% in Africa between Dec. 29 and Jan. 25, when compared with the previous four weeks. Deaths from the disease rose two-fold in the same period, with over 15,000 concentrated in 10 mainly southern and northern African nations, according to the WHO.

Over the last week, more than 175,000 new cases and over 6,200 new deaths were reported across the continent. There was a small dip in cases in South Africa, but 22 countries continue to see their numbers surge, according to the WHO.

The B1351 variant, first identified in South Africa, is "predominant and powering record case numbers in South Africa and the sub-region," the WHO said. The strain has been detected in Botswana, Ghana, Kenya, the French Indian Ocean region of Mayotte, Zambia and at least 24 non-African nations, according to the WHO.

Meanwhile, another new, highly contagious variant called B117, which was initially detected in the United Kingdom, has been found in Gambia and Nigeria.

The WHO said it is working to track and tackle new strains of the deadly virus. The U.N. agency, along with the Africa Centers for Disease Control and Prevention, has helped set up a COVID-19 genomic sequencing laboratory network with labs in the Democratic Republic of the Congo, Gambia, Ghana, Kenya, Nigeria, Senegal, South Africa and Uganda.

"In addition to the new variants, COVID-19 fatigue, and the aftermath of year-end gatherings risk powering a perfect storm and driving up Africa’s second wave and overwhelming health facilities," Moeti said. "Africa is at a crossroads. We must stick to our guns and double down on the tactics we know work so well. That is mask wearing, handwashing and safe social distancing. Countless lives depend on it."