Seasonal influenza is an annually recurring threat to residents of long-term care facilities (LTCFs) since high age and chronic disease diminish immune response following vaccination. Although immunization of healthcare workers (HCWs) has proven to be an added value, coverage rates remain low. A ready-to-use instruction manual was designed to facilitate the implementation of interventions known to increase vaccination coverage in healthcare institutions. It includes easy-access vaccination, role model involvement, personalized promotional material, education and extensive communication. We evaluated this manual during the 2017-vaccination campaign in 11 LTCFs in Belgium. Vaccination coverage before and after the campaign was recorded by the LTCFs and the usefulness of the manual was assessed by interviewing the organizers of the local campaigns. Attitudes toward vaccination and reasons for vaccination were evaluated with a quantitative survey in HCWs before and after the campaign. The mean vaccination coverage reported by the LTCFs was 54% (range: 35-72%) in 2016 and 68% (range: 45-81%) in 2017. After the campaign, HCWs were less likely to expect side effects after influenza vaccination (OR (95%CI): 0.4 (0.2-0.9)) or to oppose vaccination (OR (95%CI): 0.3 (0.1-0.9)). The majority (>60%) indicated to be well informed about the risks of influenza and the efficacy of the vaccine. The main reason for vaccination in those who previously refused it was resident protection. The manual was found useful by the organizers of the campaigns. We conclude that the use of an intervention manual may support vaccination uptake and decrease perceived barriers toward influenza vaccination in countries without mandatory vaccination in HCWs.