United says 273 employees reported they were vaccinated after the company said they would be fired over the company's strict vaccine mandate

• United's number of unvaccinated workers dropped from 593 to 320 after they faced termination.
• The carrier required all nonexempt US employees to be fully inoculated by September 27 or be fired.
• Over 99% of the company's nonexempt US workforce has been vaccinated against COVID-19.

Nearly half of United Airlines' unvaccinated workers have now provided proof of inoculation since facing termination, the carrier said Thursday.

United has the strictest employee vaccination policy of any airline in the US. On Wednesday, United announced over 99% of its 67,000-strong US workforce was vaccinated against COVID-19, minus the 3%, or roughly 2,000 employees, who applied for religious or medical exemptions and are still going to work. The airline's policy, established on August 6, said all nonexempt workers were required to be vaccinated by September 27 or be fired.

All but 593 employees were inoculated by the deadline, and United said it would begin the separation process on Thursday for unvaccinated nonexempt workers. But since Wednesday's announcement, the number of employees without proof of inoculation dropped to 320, declining by nearly half.

According to United, the reduction is driven mainly by employees uploading their vaccination cards late, and management expects the number to decrease more after individual meetings with employees find they are actually vaccinated.

"Our vaccine policy continues to prove requirements work - in less than 48 hours, the number of unvaccinated employees who began the process of being separated from the company has been cut almost in half, dropping from 593 to 320. That means 99.5 percent of United's U.S. employees have now chosen to get vaccinated, excluding those who sought an exemption," United said in a statement.

Other US airlines have yet to mandate vaccinations for employees, though some are trying to incentivize the shot through reward or punishment. Delta Air Lines announced in August that unvaccinated employees would be forced to pay an extra $200 for the company health-insurance plan, while Southwest is offering 16 hours of extra pay for inoculated workers. Southwest CEO Gary Kelly said he did not believe in the company mandating vaccinations but added that the federal government may implement requirements.

"So we at Southwest Airlines may be compelled by federal law to require employees to be vaccinated, and we will be prepared for that," Kelly told staff, according to CNBC.