A systematic review of the evidence on the effectiveness and risks of inactivated influenza vaccines in different target groups
Faculty of Medicine and Health Sciences
Vaccine / International Society for Vaccines. - Amsterdam
, p. 9159-9170
University of Antwerp
Purpose To systematically review the evidence regarding the efficacy, effectiveness and risks of the use of inactivated influenza vaccines in children, healthy adults, elderly individuals and individuals with co-morbidities such as diabetes, chronic lung disease, cardiovascular disease, kidney or liver disease and immune suppression. Methods The Cochrane database of systematic reviews was searched for relevant reviews and supplemented with searches of the Cochrane Central Register of Controlled Trials database and Medline. Two reviewers independently assessed review and trial quality and extracted data. Results and conclusions The inactivated influenza vaccine has been proven effective in preventing laboratory-confirmed influenza among healthy adults (1665 years) and children (≥6 years) (GRADE A evidence). However, there is strikingly limited good-quality evidence (all GRADE B, C or not existing) of the effectiveness of influenza vaccination on complications such as pneumonia, hospitalisation and influenza-specific and overall mortality. Inconsistent results are found in studies among children younger than 6 years, individuals with COPD, institutionalised elderly (65 years or older), elderly with co-morbidities and healthcare workers in elderly homes, which can only be explained by bias of unknown origin. The vaccination of pregnant women might be beneficial for their newborns, and vaccination of children might be protective in non-recipients of the vaccine of all ages living in the same community (one RCT, Grade B evidence). Highlights ► The content of 11 Cochrane reviews regarding the value of inactivated influenza vaccines (TIV) summarized and updated. ► Significant efficacy of TIV in healthy adults and children (>6 years, Grade A evidence). ► No efficacy of TIV in young children (<2 years) or institutionalised elderly. ► Inconsistent results in children (<6 years), individuals with COPD, institutionalised elderly, elderly with co-morbidities and healthcare workers in elderly homes. ► Striking lack of sound evidence for the effect of TIV on influenza complications (GRADE B, C or not existing).