Schools fully reopened across Kenya on Monday for the first time in nearly 10 months.

The Kenyan government shut down schools nationwide in March, after the East African nation confirmed its first COVID-19 case. The government reopened schools for students in grades 4, 8 and 12 who were preparing for final exams. The remainder -- some 16 million schoolchildren - were expected to return to classrooms Monday.

The government has asked school officials and teachers to implement public health measures, such as social distancing and hygiene guidelines, to prevent the spread of the novel coronavirus.

Still, teachers have expressed concern over the safety of their students and themselves amid the pandemic. Wilson Sossion, secretary-general of the Kenya National Union of Teachers, told BBC's "Newsday" that the level of preparation on COVID-19 safety measures ahead of the reopening was "quite inadequate."

"When you give such directives to schools and you don't give them funding," Sossion said, "how are they expected to implement?"

Kenya, a country of 51 million people, has reported more than 96,000 confirmed cases of COVID-19 since the start of the pandemic, including at least 1,685 deaths, according to the latest data from the Africa Centers for Disease Control and Prevention.

More than 3.3 million people went through airport security checkpoints across the United States over the holiday weekend, despite public health guidance against traveling due to the coronavirus pandemic.

The Transportation Security Administration (TSA) said it screened 805,990 individuals at checkpoints nationwide on Friday, New Year's Day, along with 1,192,881 on Saturday and 1,327,289 on Sunday. Sunday's total was the highest checkpoint volume that TSA has recorded since the pandemic began.

That means the total for the entire holiday travel period -- beginning Dec. 18 and ending Sunday -- was more than 17.7 million people, which is far higher than what analysts had been forecasting.

ABC News' Gio Benitez, Alexandra Faul and Sam Sweeney contributed to this report.

U.S. Secretary of Health and Human Services Alex Azar said the nationwide distribution of COVID-19 vaccines is still on track and that he's "surprised there haven't been more glitches."

"We said our goal was to have 20 million first doses available in the month of December. Those are available, but there's a lag between doses being available, them being ordered by the providers in the states, shipping and then eventual vaccination, especially when you have Christmas and New Year's in the middle," Azar told ABC News' Robin Roberts in an interview Monday on "Good Morning America."

"This is just -- it's normal," he added. "This is the largest vaccination campaign in the history of the United States. I'm actually surprised there haven't been more glitches that we've seen so far."

Azar's comments come after the Centers for Disease Control and Prevention published an update on the country's vaccine rollout, showing that 13,071,925 doses have been distributed and 4,225,756 have been administered as of 9 a.m. ET on Jan. 2. Some states have faced delays or other issues with their rollouts, with people being turned away at vaccination sites.

But Azar said there's been "a very rapid uptick" in just the last 72 hours of reporting, with an additional 1.5 million vaccine doses administered.

"I'm very hopeful that we're going to see a continued rapid uptick in that," he said. "Our states are on it, w're working with our governors, we're providing them help."

Tokyo and other areas of Japan may enter a state of emergency as COVID-19 infections continue to climb.

"The number of people infected with the novel coronavirus has not gone down, but rather has remained high in Tokyo and the neighboring prefectures," Japanese Prime Minister Yoshihide Suga said at a press conference Monday. "With that in mind, we thought we needed to send a stronger message."

Suga did not say when a state of emergency would go into effect but that the "details will be decided quickly." The announcement is expected to come before the end of the week.

Declaring a state of emergency would give the governors of those respective regions the authority to ask residents for cooperation in efforts to stem the spread of the virus. There are currently no legal ramifications for non-compliance.

Suga's predecessor, Shinzo Abe, declared a nationwide state of emergency relatively early in the pandemic in April, which lasted for a month. At that time, residents were asked to reduce person-to-person contact by 80% and to practice "jishuku," or "self-restraint," by staying at home and closing non-essential businesses.

Suga has said any upcoming state of emergency will be implemented in a "limited and focused" manner, leading some to speculate that the demands won’t be drastic. Restrictive measures could also disrupt preparations for the 2020 Summer Olympics in Tokyo, which was postponed to this year.

During Monday's press conference, Suga also pledged to speed up efforts to approve COVID-19 vaccines and to begin immunizing the country's senior citizens, health care workers and nursing home employees in late February.

COVID-19 infections soared in Tokyo over the holidays. On New Year's Eve, the Japanese capital reported over 1,300 newly confirmed cases for the first time in a single day. Nationwide, more than 245,000 cases have been confirmed since the start of the pandemic, including at least 3,645 deaths, according to the latest data from the Japanese Ministry of Health, Labour and Welfare.

Japan also recently detected several confirmed cases of the new, more contagious variant of the novel coronavirus that was first identified in the United Kingdom last month.

ABC News' Anthony Trotter contributed to this report.