Influenza vaccination in non-institutionalized elderly: a population-based study in a medium-sized city in Southern Brazil.

Vaccination is the most effective measure to prevent the complications of influenza. This population-based study aimed to estimate influenza vaccine coverage in non-institutionalized elderly, analyze the factors involved in lack of influenza vaccine uptake, and identify post-vaccination adverse effects. The study population lived in an urban neighborhood in Southern Brazil, and the sample consisted of 425 elderly. A total of 396 elderly individuals (age 60-95 years) were interviewed. Although 100% of the sample reported knowing about the vaccine, only 5.3% referred to their personal doctor as the source of information. Among elders that had not received the vaccine, 83.2% were explicit about not wanting to take it. The main reasons were fear of adverse effects and disbelief in the vaccine's effectiveness. However, the actual prevalence of adverse effects was low. Age, smoking, and lack of a doctor's appointment in the previous year were independently associated with vaccine non-compliance. The results show that improvements are needed in the immunization campaign, especially targeting elders less than 70 years of age and smokers.