In this review, we identified 12 studies that evaluated interventions to increase influenza vaccination coverage among health care personnel in long-term care facilities, hospitals and primary health care settings. Of the five recommended campaign components to increase vaccination rates among health care personnel (), the most common strategies were education or promotion and improving access to the vaccine. None of the campaigns in the included studies reached the recommended level of 90% uptake of vaccine among health care personnel.
In nonhospital health care settings, campaigns involving only education or promotion resulted in small increases in vaccination rates relative to other interventions. A combination of education or promotion and improved access to the vaccine yielded greater increases in coverage among long-term care workers. Coverage was highest in the study in which each worker had a personal interview session with a member of the study team.17
Only one campaign had more than two components, so no conclusions can be drawn about campaigns using other combinations of components.
In hospital settings, education or promotion resulted in small improvements in coverage. Only Ohrt and McKinney20
found a substantial improvement, which might have been due in part to low vaccine uptake at baseline. Similarly, campaigns involving only improved access to the vaccine had minimal impact. Conversely, campaigns involving legislative or regulatory components (e.g., mandatory declination form, mandatory masks for unvaccinated personnel) achieved higher rates than other interventions.
The major shortcomings of the reviewed studies were failure to report the number of health care personnel exposed to the campaign and the number of health care personnel for whom there was no follow-up. Ascertainment of vaccination status often excluded off-site vaccination, which resulted in underestimation of coverage. To assess the association between a campaign and the subsequent vaccination rate, health care personnel should be tracked for their exposure to the intervention and their resulting vaccination status. Rates stratified by level of direct contact with patients may inform future efforts to target specific high-risk groups.
Among the excluded studies, single-group before-and-after studies and cross-sectional studies were the most common study designs. Such studies are more logistically feasible than more rigorously designed studies, but they do not control for factors outside the “intervention” that may inflate or diminish the observed outcome. Organizers conducting campaign evaluations for before-and-after studies should consider having a comparable control group. Organizations are encouraged to monitor and report annual vaccination rates for health care personnel over time, to improve the accuracy of observed outcomes and to provide multiple observation points for an interrupted time series design.
The limitations of this review included inability to pool data across studies because of heterogeneity in study methods and campaign components. In addition, the study methods had several risks of bias that might have generated misleading results, such as lack of comparable baseline characteristics across study groups. In our review, we did not assess the impact of pandemic influenza programs. Three of the excluded studies26–28
incorporated “pandemic vaccination drills” as part of their respective seasonal campaigns. The effect of pandemic influenza on vaccination coverage for seasonal influenza among health care personnel is unknown.
This review revealed gaps in the literature about the appropriate campaign components for increasing influenza vaccination among health care personnel. To determine the appropriate design and components of influenza vaccination campaigns for health care personnel, rigorously designed studies assessing the effect of various campaign components design are needed.