There is a significant body of evidence that supports the vaccination of frontline staff a sample appears below:

• PHE and NHS Employers: Healthcare worker vaccination: clinical evidence (updated September 2018).
• Royal College of Physicians: Healthcare worker influenza vaccination and sickness absence – an ecological study
• Effects of influenza vaccination of health-care workers on mortality of elderly people in long-term care: a randomised controlled trial. Carman WF1, Elder AG, Wallace LA, McAulay K, Walker A, Murray GD, Stott DJ.
• Influenza vaccination of health care workers in long-term-care hospitals reduces the mortality of elderly patients. Potter J1, Stott DJ, Roberts MA, Elder AG, O’Donnell B, Knight PV, Carman WF.