The flu vaccine protects many people against seasonal flu. Yet, we do not typically develop immunity to all strains of the influenza virus. St. Jude scientists have found a clue as to why our immune systems do not target virus components that all flu strains share.
“The study shows for the first time that antibodies that bind more than one influenza subtype can worsen autoimmune disease. So, these antibodies could be harmful in the presence of additional inflammation or susceptibility to autoimmunity,” said Maureen McGargill, PhD, Immunology.
Scientists showed that antibodies targeting the regions of virus shared between influenza subtypes can worsen disease in some models of autoimmunity. Autoimmune disease occurs when the immune system attacks healthy tissue. The researchers found that antibodies recognizing shared regions of influenza virus also bound to healthy-tissue proteins related to autoimmunity.
The results come as scientists work to develop a universal flu vaccine to protect against most flu strains. The findings show that vaccine makers must consider how such vaccines may affect people at risk for autoimmune disease.
“Research should move forward improving influenza vaccines. But, our work suggests that it's important to be sure you do not increase antibodies that might intensify other diseases,” McGargill said.
Cell Reports published this work.