Sept 23 (Reuters) - Delta Air Lines (DAL.N) said on Thursday its employee vaccination rate against COVID-19 had risen to 82%, weeks after announcing a monthly health insurance surcharge for unvaccinated workers. The U.S. airline last month said employees will have to pay $200 more every month for their company-sponsored healthcare plan if they choose to not be vaccinated against COVID-19. read more Delta said financial incentives such as an additional day of paid time off and $100 in health rewards, allowed it to vaccinate nearly 70% of its employees by June. United Airlines (UAL.O) on Wednesday said more than 97% of its U.S. employees have been vaccinated ahead of the company"s Sept. 27 deadline for staff vaccination. read more