Influenza vaccines: new developments.
Current inactivated influenza vaccines are being produced with three influenza virus strains that are recommended annually by the World Health Organization on the basis of information obtained from global influenza surveillance. The use of these vaccines, for which the antigens are produced in embryonated chicken eggs, can result in a significant reduction of influenza-related morbidity and mortality. Nevertheless, there is still a demand for vaccines with a higher efficacy that can be produced more rapidly and more flexibly in response to an epidemic or a pandemic. New developments in the field of influenza vaccine preparation include novel vaccine production technologies, reverse genetics technology for the generation of vaccine strains and novel adjuvants for the improvement of vaccine immunogenicity.