Chicago teachers voted Wednesday to accept the deal made by the union and city to re start in-person classes.

The deal ended the five-day standoff after the union voted to switch to remote learning due to the omicron surge.

Union leaders made a tentative agreement on Monday and urged teachers to back the deal despite frustration that the district wouldn't grant demands for widespread coronavirus testing or commit to districtwide remote learning during a COVID-19 surge.

The final agreement will expand COVID-19 testing and create standards to switch schools to remote learning.

The deal also resulted in the purchase of KN95 masks for students and teachers and bigger incentives to attract substitute teachers. The city also agreed to give teachers unpaid leave related to the pandemic.

The U.S. Army released an update on the vaccine status of its members.

As of Jan. 11, 96% of members are fully vaccinated against COVID-19 and 97% have at least one dose, according to the Army.

All armed service members are mandated to be vaccinated against the coronavirus.

Around 18,000 members remain unvaccinated, the data showed.

The Army has chosen not to discharge unvaccinated soldiers but instead "flag" them so they’re not promoted and are not allowed to re-enlist.

"To date, Army commanders have relieved a total of six active-duty leaders, including two battalion commanders, and issued 2,994 general officer written reprimands to soldiers for refusing the vaccination order," the Army said in a news release.

-ABC News' Luis Martinez

The U.S. government has purchased an additional 500,000 doses of Evusheld, AstraZeneca's monoclonal antibody drug, to be given before exposure to COVID-19, the company announced. This is on top of the 700,000 Evusheld doses already purchased.

White House officials previously said over 500,000 doses would be stockpiled in January and "significantly more" would be purchased by March."

Evusheld was authorized in December 2021 and is the first monoclonal therapy meant to be used in advance of an eligible person's exposure to COVID-19.

However, it's not meant for a wide group of people: this therapy is only authorized for immunocompromised people who may not have developed an optimal immune response to their vaccine. This therapy is also for people with a history of severe adverse reactions to a COVID-19 vaccine and thus aren't recommended to get vaccinated.

Evusheld is not authorized as a way to treat COVID-19 after testing positive.

-ABC News' Sasha Pezenik

More than 15 million new COVID-19 cases were reported globally last week, according to the World Health Organization.

"By far the most cases reported in a single week, and we know this is an underestimate," WHO Director-General Dr. Tedros Adhanom Ghebreyesus said Wednesday.

He said this "huge spike" is driven by omicron.

"While omicron causes less severe disease than delta, it remains a dangerous virus, particularly for those who are unvaccinated," Tedros warned.

WHO officials said new vaccines may be needed for different variants, and until those vaccines are developed, the current vaccines may need to be updated.

-ABC News' Christine Theodorou

Russian officials are warning that an omicron-fueled wave of COVID-19 infections will soon hit, amid fears about how deadly a surge of the highly contagious variant -- even if milder -- might be in a country with a low vaccination rate.

Russian Deputy Prime Minister Tatiana Golikova, who is overseeing the COVID-19 response, and Moscow Mayor Sergey Sobyanin said Wednesday that the situation could be "more critical" than previous waves of infections in Russia -- a worrying prospect since earlier waves led to a high number of deaths.

Russia has reported more than 312,000 fatalities from COVID-19 since the start of the pandemic, according to data compiled by Johns Hopkins University. However, the country registered just under 1 million excess deaths in 2021.

The Russian government has said the country will soon see six-figure daily cases. Less than 50% of Russians are fully vaccinated against COVID-19, amid widespread reluctance across the nation.

Russian President Vladimir Putin, who has largely tried to downplay the scale of his country's COVID-19 outbreak, warned Wednesday of the imminent increase in infections. Putin said Russia is "on the threshold of possible new outbreaks."

Meanwhile, Russian Health Minister Mikhail Murashko said the country is at a "turning point," which will decide how bad the wave will be. Russian authorities are calling for people to take precautions and observe social distancing measures. However, there are relatively few restrictions in most parts of the country.

Denis Logunov, deputy director of Russia's Gamaleya National Center of Epidemiology and Microbiology, said Tuesday that the nationwide number of omicron cases is expected to rise considerably in late January and early February. The World Health Organization's regional director for Europe, Dr. Hans Kluge, also warned Tuesday that omicron is expected to infect more than half of Europe's population within the next two months.

-ABC News' Patrick Reevell