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

Spain has reported more COVID-19 reinfections in a recent span of two weeks than it has during the rest of the pandemic, according to the latest data from a Spanish public health research institute.

Data from the Carlos III Health Institute shows there were 20,890 repeat infections reported in Spain from Dec. 22, 2021, to Jan. 5, 2022. That figure tops the 17,140 reinfections reported in the European country from the start of the pandemic in March 2020 to Dec. 22, 2021. The data includes confirmed, probable and possible cases.

Alfredo Corell, an immunology professor at Spain's University of Valladolid, told Spanish news site NIUS that the rising number of reinfections were due to the new and highly transmissible omicron variant.

"Prior to this variant, reinfections were anecdotal at the global level," Corell told NIUS. "Omicron has changed this paradigm."

In southern Africa, where the variant was first identified in November, preliminary research suggests that omicron is three times more likely to cause reinfections compared to other known variants of the virus, including the highly contagious delta. However, symptoms of reinfected individuals appear to be mild, according to Anne von Gottberg, a microbiologist at South Africa's National Institute for Communicable Diseases who is studying omicron.

"Previous infection used to protect against Delta," von Gottberg said during a press briefing on Dec. 2. "But now, with Omicron, that doesn't seem to be the case."