One of the South African scientists who helped identify the omicron variant took to Twitter to slam the travel bans imposed on southern African countries as a result of their discovery.

Tulio de Oliveira, director of the Center for Epidemic Response and Innovation in Stellenbosch, South Africa, tweeted Monday night that he had "spent a big part" of his day speaking with genomic and biotech companies because "soon" his team "will run out of reagents as airplanes are not flying to South Africa."

In a series of tweets last week, de Oliveira urged the world to "provide support to South Africa and Africa and not discriminate or isolate it."

"We have been very transparent with scientific information. We identified, made data public, and raised the alarm as the infections are just increasing. We did this to protect our country and the world in spite of potentially suffering massive discrimination," he tweeted.

"This new variant is really worrisome at the mutational level. South Africa and Africa will need support (financially, public health, scientific) to control it so it does not spread in the world. Our poor and deprived population can not be in lockdown without financial support," he said in another tweet.

De Oliveira, who is leading a team of scientists analyzing the genomic sequencing of the new variant, issued an appeal to billionaires and financial institutions to support South Africa and the African continent.

"We do have funding for science, but South Africa and Africa need financial help to support their deprived population and health system," he tweeted. "By protecting its poor and oppressed population we will protect the world."

Japan confirmed on Tuesday its first case of the omicron variant, according to Chief Cabinet Secretary Hirokazu Matsuno.

Matsuno told a press conference that the patient is a man in his 30s who tested positive for COVID-19 upon arrival at Japan's Narita International Airport on Sunday after traveling from Namibia. A genome analysis confirmed Tuesday that he was infected with the new variant, which was first identified in southern Africa last week.

The man was isolated and is being treated at a hospital, according to Matsuno, who refused to disclose the patient's nationality. His travel companions and the passengers who sat nearby have been identified and referred to Japanese health authorities, Matsuno said.

Earlier this week, Japan announced that it will ban all foreign visitors starting Tuesday as an emergency precaution against omicron, which the World Health Organization has classified as a "variant of concern." The government is also requiring Japanese nationals and foreigners with resident permits to quarantine 14 days upon entry.

-ABC News' Anthony Trotter

A third person in Canada has tested positive for the omicron COVID-19 variant, health officials announced Monday.

The province of Quebec has confirmed its first case of the variant, Quebec Health Minister Christian Dube told reporters at a press conference in Montreal.

The woman who tested positive had traveled to Nigeria, said Canada Director of Public Health Dr. Horacio Arruda.

Two cases of the variant had been previously detected in Ontario, officials said Sunday.

-ABC News' Darren Reynolds

Pfizer is going to ask the Food and Drug Administration in the coming days to authorize COVID-19 booster shots for 16- and 17-year-olds, a source familiar with the discussions confirmed to ABC News.

This would expand booster access from everyone over 18 to everyone over 16.

Pfizer vaccines were authorized for adolescents in May, so many fully vaccinated people are nearing their six-month mark amid growing concern over the omicron variant.

-ABC News' Cheyenne Haslett