A meta-analysis study on the vaccination effectiveness of influenza and interpretation regarding economic aspects

Health "is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity". It is also a field of study for all sciences, as it is a factor that affects the "individual", the building block of society, in all contexts. The fact that the workforce, that is, the individual, has been accepted as the essential economic input for centuries requires that health be integrated with economics. Governments, especially in developed countries, allocate as much of their economic resources as possible to health. In this framework, the requirement for influential health applications comes to the fore. Immunisation is one of the most crucial elements in providing preventive health strategies and is very financially and medically effective. Active immunisation or vaccination is critical in preventing diseases such as "influenza", which have a very high economic and social burden. Accordingly, in this thesis, three meta-analyses were conducted separately to examine the vaccination activities against three strains of influenza. The results observed in 152 studies in Web of Science (Web of Knowledge) and PubMed databases were examined in order to conduct a systematic review and meta-analyses. With the meta-analyses carried out with the Comprehensive Meta-Analysis Software (CMA) package program, the best vaccination performance was observed against A(H1N1) at 60.3%, following B at 51.1% and worst against A(H3N2) at 20.4%. In other words, current vaccines provide insufficient protection against influenza A(H3N2) compared to the vaccines against influenza B(any lineages) and influenza A(H1N1). Hence, vaccine development improvements are necessary to increase protection, especially against the H3N2 strain of influenza. The findings from this thesis shed light on the number of resources that can be allocated to each influenza strain vaccine while determining the health-economic strategies that ensure the cost-effectiveness of influenza vaccines.