The Potential Utility of Adjuvanted Seasonal Influenza Vaccine for Travelers

Abstract

The recently published report and commentary on the risks of acquiring influenza during travel highlights the particular difficulty of protecting persons traveling from the northern to the southern hemisphere and vice versa. 1,2 The frequency of infections acquired in these circumstances was clearly documented by the experience of Mutsch and colleagues at the University of Zurich (northern hemisphere), where influenza cases were encountered throughout the year, comprising infections acquired in the southern hemisphere and equatorial regions where influenza may be transmitted year‐round. 3–5 The approach of importing vaccines from the alternate hemisphere to address the needs of such travelers might be feasible in some countries under a compassionate use authorization, but it would be unrealistic to believe that manufacturers could license alternate hemisphere formulations for such limited use. The US Centers for Disease Control (CDC) and others have thus recommended northern hemisphere formulation vaccines for persons traveling to the southern hemisphere but the short shelf‐life and uniform expiration of northern hemisphere vaccines in June is an important limitation. This is especially true for the large numbers of travelers departing in July and August, during the typical northern hemisphere holiday season when … Corresponding Author: Theodore F. Tsai, MD, MPH, FIDSA, Novartis Vaccines, 350 Mass Ave, Cambridge, MA 02139, USA. E‐mail: theodore.tsai{at}novartis.com