The Middle East Respiratory Syndrome infected 186 people and killed 36 of them in the South - the largest outbreak outside Saudi Arabia where the virus originated.
The outbreak - which peaked in June and July before being declared over in December - took a heavy toll on the nation's economy, especially tourism-related business.
The airline's net loss for 2015 widened to 703 billion won (USD 582.2 million), up 53.6 percent from a loss of 457.8 billion won in 2014, Korean Air said in a statement.
Sales fell 3.1 per cent year-on-year to 11.5 trillion won.
The number of foreign visitors to the South dropped 6.8 per cent to 13.2 million last year, the first decline in 12 years.
