Mandatory influenza immunisation of health-care workers

Abstract

Seasonal influenza imposes an enormous but poorly defined burden of excess deaths, hospital admissions, and health-care costs, and often spreads within health-care facilities. Hospital patients with influenza are a potential source of infection for health-care workers that are not immunised, with attack rates among health-care workers of 18–24%.1 Unfortunately, health-care workers infected with influenza often continue to work, despite symptoms, with potentially devastating consequences for high-risk patients, including those who are very young, elderly, or immunocompromised—for example, patients receiving bone-marrow transplants have a high risk of pneumonia and death from influenza.2 Trivalent subunit influenza vaccines are 70–90% effective3 and safe, with mild side-effects in less than 10% of recipients.4 Immunisation of health-care workers can reduce exposure to, and illness and death from, influenza among patients in long-term care facilities5 even with modest uptake rates6 (at an estimated cost of £51–405 per life-year saved), as well as reducing infection and absenteeism among health-care workers that have been immunised (with estimated savings of £12 per vaccinee).5 In a bone-marrow-transplant unit in the USA, increasing immunisation uptake from 12% to 58% among health-care workers, was associated with a reduction in nosocomial influenza infections from 14 to 4 cases per 10 000 patients days.7 Despite this evidence and recommendations by major health authorities for yearly immunisation of health-care workers,8 uptake is often poor (less than 30%). Immunisation uptake rarely exceeds 60%, even when vaccine is free and easily accessible,5 and 9 which is inadequate to protect the most vulnerable patients, many of whom are unimmunised because of immunosuppression or comorbidities. Uptake can be increased by various interventions, including staff education, active promotion, incentives, declination forms, clinical leadership, and provision of free vaccine at convenient locations, such as mobile carts,8 and 10 but increases are often modest and difficult to sustain over successive seasons