WEDNESDAY, March 13 (HealthDay News) -- Flu vaccines protect people by activating white blood cells that, in turn, boost the development of antibodies to the flu, a new study suggests.
The finding may lead to more effective vaccines -- especially for people whose immune system isn't robust enough to fully protect them from the flu, such as the elderly, the study authors said.
"It is well known that CD4 T cells are important for the generation of antibody responses," said lead researcher Dr. Hideki Ueno, an investigator at the Baylor Institute for Immunology Research in Dallas.
"Most importantly, we found that the appearance of these cells in blood correlated with the development of protective antibodies against flu. Therefore, these cells appear to be very important for the successful flu vaccination," he said.
The failure of older people to generate a protective antibody response after a flu vaccine might be associated with the failure to produce these CD4 T cells, Ueno said.
This year, for example, the flu vaccine was only 9 percent effective in older people against the dominant H3N2 strain, according to the U.S. Centers for Disease Control and Prevention. Finding ways to boost a vaccine's effectiveness is especially important for seniors, who are at higher risk of complications from the flu and are more likely to die from them.
One way to help high-risk people might be to identify those whose immune response is likely to be insufficient to fully protect them from the flu, the researchers said.
"You could potentially screen people for their antibody response -- particularly young children and the elderly," said Andrea Sant, a professor with the department of microbiology and immunology at the University of Rochester, in Rochester, N.Y.
This screening could also be important during flu pandemics, said Sant, who was not involved with the study.
All rights reserved