Centene Corp. said it would eliminate 4,500 jobs, including 3,000 current employees and another 1,500 open positions, as it focuses on “innovation, growth and agility” after posting a $12 million fourth-quarter loss. However, its overall fourth-quarter and full-year 2020 financial results largely met analysts’ expectations, and company executives pledged strong growth in both their Medicaid and Medicare business lines in 2021.