Vacina contra Influenza: impacto da morbimortalidade e fatores relacionados à adesão em idosos

Abstract

Influenza is a disease that affects the respiratory system and can cause more serious damage in risk groups, in which older people are inserted. In order to reduce morbidity and mortality due to the disease, a public vaccination policy was created through annual campaigns, aiming at high and homogeneous coverage rates. However, some factors may influence the adherence of older adults to the vaccine. The aim was to assess the impact of influenza vaccination on influenza morbidity and mortality in Brazil and to analyze factors related to the older population's adherence to influenza vaccine in the city of Três Lagoas - MS. All ethical issues were observed. This thesis is structured in three papers. The first aimed to analyze the impact of influenza vaccination on morbidity and mortality from influenza in the elderly from 2010 to 2019 in the regions of Brazil. It is an ecological epidemiological study with data from the Information System of the National Immunization Program, Hospital Information System, and Mortality Information System, referring to Brazil and its regions. The data included influenza vaccination coverage rates and morbidity and mortality from causes related to influenza and pneumonia in the elderly. Simple linear regression models were used. There was an increase in vaccination coverage in the period, and the goal of 80% coverage was reached in all regions since 2011. The increase in vaccination coverage was directly related to the increase in morbidity and mortality. However, it was detected that the data used to calculate vaccination coverage were out of date. The second paper aimed to identify the sociodemographic, health and knowledge variables about vaccination related to the adherence to influenza vaccine in older adults. A sociodemographic and health questionnaire and questions related to influenza vaccination were applied in n = 172 elderly people. Prevalence ratios and Bayesian learning networks were used to analyze the data. Most of the elderly were female, with a partner, between 60-69 years old, and with elementary education. The majority of them knew the National Immunization Program (PNI) and trusted it, knew that the influenza vaccine is indicated for the elderly and used to take it annually. The rate of adherence to the influenza vaccine in the previous campaign was 91.3%. Elderly people with neuropsychiatric diseases, who received the vaccine annually and who had taken it in 2018, 2016 and 2015 had a higher prevalence of adherence. The Bayesian networks showed that knowing that the PNI exists leads to trust in it, which leads to annual vaccination. The aim of the third paper was to know the reasons for elderly adherence to the influenza vaccine before and during the Covid-19 pandemic. It is a quantitative and longitudinal study. At the beginning of 2020, 86 elderly people were evaluated in person. They were questioned about adherence to the flu vaccine in 2019, and the reasons for adherence or non-adherence. The second assessment was between August and October 2020, by telephone. The questions were about vaccine adherence in 2020 and the reasons. Most of the sample were women, half had a partner and the average age was 69.1 years. Vaccine adherence in 2019 was 90.73%, with the majority taking the vaccine because they believe it really works and that it is important to get vaccinated. Among those who did not adhere, the lack of knowledge about the campaign and the fact that they did not catch the flu prevailed. In 2020, adherence was 86%, with the majority adhering due to the availability of the vaccine at the health service and the loss of the vaccine's effect after one year. The most prevalent reasons for non-adherence were the fear of leaving home due to the pandemic and the lack of professional guidance. In conclusion, maintaining high vaccination coverage can prevent the impact of influenza being even greater on morbidity and mortality in the elderly. The pandemic may have influenced influenza vaccination rates in the elderly. The promotion of influenza vaccination should disseminate knowledge about the importance of annual vaccination, in order to obtain high and homogeneous vaccine coverage.