MedicalResearch.com: What is the background for this study? What are the main findings?
Response: The consequences of influenza in adults are mainly time off work. Only vaccination of pregnant women is recommended internationally, while mass vaccination of healthy adults is still matter of debate.
The aim of this Cochrane Review is to assist informed decision making summarizing research that looks at the effects of immunizing healthy adults with influenza vaccines during influenza seasons.
The review process found 52 clinical trials of over 80,000 adults. Only around 15% of the included studies were well designed and conducted. We focused on reporting of results from 25 studies that looked at inactivated vaccines. Injected influenza vaccines probably have a small protective effect against influenza and influenza-like illness (ILI_ (moderate-certainty evidence), as 71 people would need to be vaccinated to avoid one influenza case, and 29 would need to be vaccinated to avoid one case of ILI. Vaccination may have little or no appreciable effect on hospitalizations (low-certainty evidence) or number of working days lost. Continue reading