International meeting on influenza vaccine effectiveness, 3-4 December 2012, Geneva, Switzerland.

On December 3–4 2012, the World Health Organization convened a meeting of influenza vaccine effectiveness (VE) experts from over 25 countries in Geneva, Switzerland, to review recent developments in the global influenza vaccine landscape and evaluate approaches to determining the effectiveness of influenza vaccine products among target populations. Vaccine manufacturers from Thailand, Vietnam, India, and Brazil shared recent advances illustrating the expansion of influenza vaccine production worldwide. Randomized controlled trials are underway in several low and middle-income countries including India, Thailand, Bangladesh, and South Africa, to fill knowledge gaps in target populations such as children and pregnant women. National and international networks in the United States, Canada, Europe, Latin America and Australia are conducting multi-site observational studies with shared methodologies to generate national influenza VE estimates and pool data for regional estimates. Standardized VE estimation methods are key to generating point estimates that are comparable internationally and across different settings.