Even a Small Stride Can Have a Significant Impact:Enhancing the Effectiveness of Influenza Vaccines

Influenza viruses contribute substantially to respiratory diseases worldwide,including severe lower respiratory tract illnesses,hospitalization,and death.There are approximately a billion cases of seasonal influenza worldwide annually,including 3 to 5 million cases of severe illness and 290,000 to 650,000 respiratory deaths.[1]Vaccination remains the best available intervention to prevent morbidity and mortality caused by influenza viruses circulating in humans,especially for older people with underlying health conditions,such as asthma,diabetes,and cardiovascular diseases.Infection with influenza virus can cause the greatest morbidity and mortality effects.[2]However,the effectiveness of traditional standard-dose inactivated influenza vaccines is not satisfactory,with vaccine effectiveness ranging from 20%in years in which the vaccine is antigenically mismatched to the circulating viral strain[3]to 40%to 60%in years in which the vaccine is antigenically well matched.[4]