Influenza vaccine coverage survey among high risk groups in Malta.

Abstract

Influenza illness affects up to 20% of the population annually. Whilst it is a mild disease in otherwise healthy young persons, in older persons and those with chronic conditions, it can result in increased hospital admissions, increased morbidity and mortality. Seasonal influenza vaccination is therefore recommended in :Malta for all persons aged 55 years or over and all persons with chronic medical conditions making them at high risk of complications from Influenza. Healthcare workers should also be vaccinated in order to reduce sick episodes and to protect vulnerable patients. No data has been published in Malta on vaccination coverage rates among these at risk groups. The main objective of this thesis was to measure vaccination coverage rates among these target groups in order to inform policy makers and recommend ways of improving vaccinatlon coverage. This thesis reports on three studies, a telephone survey among persons over 55 years of age, a mailed questionnaire to persons of any age suffering from chronic conditions and a survey of healthcare workers employed in various settings. Vaccination coverage was estimated for all groups and risk factors for vaccination identified. Reasons for non-vaccination were also explored. Vaccination coverage rates were 56.3% among persons aged 55 years or over; 55.3% among all persons with chronic diseases and 56.5% among healthcare workers. Vaccination coverage was highest among persons aged over 65 years who suffered from chronic conditions. Persons over 55 years of age were more likely to be vaccinated if they believed that influenza vaccination was effective, believed influenza to be a serious illness and were over 65 years of age. Persons with chronic conditions were more likely to be vaccinated if they were not employed, did not believe influenza vaccine cause influenza illness and believed that the vaccine was effective. Among healthcare workers, vaccination coverage depended mainly on their place of employment, if they did not believe that vaccination did caused influenza illness and if they believed that influenza vaccination was effective. Among all groups, being previously vaccinated was strongly associated with vaccination during the study season.