Washington, June 8 (IANS) A universal flu vaccine targeting a protein common to all strains of influenza A has safely produced an immune response in humans. If proven effective, the vaccine could eliminate the practice of creating a new flu vaccine annually to match predicted strains, with major implications for global health.

The results of clinical trials led by the University of Texas Medical Branch (UTMB), Galveston, with biotech company VaxInnate were funded by $9.5 million grant from the Bill and Melinda Gates Foundation, the journal Vaccine reports.

The vaccine candidate, VAX102, targets a protein known as M2e, found on the surface of the influenza A virus, that has remained relatively unchanged over the last century, according to a Texas statement.

The M2e antigen had been completely unchanged from 1918 until the recent pandemic, making it of interest to researchers searching for a target for the immune response to flu that would be stable over many seasons.

Unlike traditional flu vaccines, which target antigens that change continuously, the prototype VAX102 represents a vaccine that would not require annual updates, an important barrier to flu prevention worldwide.

The technology used to produce the candidate vaccine would eliminate many of the limitations of current flu vaccines, including limited production capability and the inability to change the target antigen should the vaccine not match the circulating strains.

"As we saw in the 2009 influenza pandemic, there is a great public and global health need for a rapid, scalable model for vaccine production," said lead author Christine B. Turley, paediatrician and member of UTMB's Sealy Centre for Vaccine Development.

"If ultimately proven effective, VAX102 will meet this need and offer a completely new approach to global flu prevention and control."