A high-dose flu vaccine is showing promising results among people aged over 65, who make up 90% of the 36,000 annual influenza-associated deaths in the US.
Sanofi pasteur has announced that an investigational vaccine has shown increased immune responses among that age group compared with the standard flu vaccine.
The candidate high-dose intramuscular formulation of the influenza vaccine is now being developed by the company.
The US Centers for Disease Control and Prevention (CDC) says that the currently available inactivated vaccine does reduce flu-related deaths in older people.
But their immune system tends to weaken and they are less responsive to vaccination and less able to mount an immune response when infected with the influenza virus.
Said Ann Falsey, associate professor of medicine, University of Rochester School of Medicine: "Development of an influenza vaccine that will provide an improved immune response in older adults is important because this population has the highest rates of complications from influenza including hospitalisation and death."
Sanofi pasteur's work was reported at the 48th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC)/Infectious Diseases Society of America (IDSA) 46th annual meeting.