Universal flu vaccine candidate under US clinical trial

American scientists started the clinical trial of a universal influenza vaccine candidate for its safety and ability to induce an immune response in healthy volunteers.

The researchers at the National Institute of Allergy and Infectious Diseases (NIAID), under the U.S. National Institutes of Health, developed the experimental vaccine, which is designed to teach the body to make protective immune responses against diverse influenza subtypes by targeting a portion of the virus that varies relatively little from strain to strain.

The universal influenza vaccine can provide long-lasting protection for all age groups from multiple influenza subtypes, including those that might cause a pandemic.

The trial will gradually enroll at least 53 healthy adults aged 18 to 70 years and investigators hope to understand how participants’ immune responses to the experimental vaccine may vary based on age and the likelihood of their previous exposure to different influenza variants.

HA, which enables the influenza virus to enter a human cell, is composed of a head and stem region. The HA head constantly changes with a phenomenon called “antigenic drift,” so traditional flu vaccines, mostly directed toward the head, must be updated each year.