Immune Response to Flu Vaccine May Be Linked to Ethnicity, Study Says

To get the shot, or not to get the shot? That’s a question many people struggle with during flu season. While some may sing the shot’s praises, others cite its mere 23 percent effectiveness rate.

A new study from Dana-Farber Cancer Institute (DFCI) may help explain that lackluster percentage. Researchers at DFCI found that an individual’s immune response to the flu vaccine may be linked to his or her ethnicity.

“This will change our understanding of how to achieve universal vaccine responsiveness in a population,” Wayne Marasco the leader of the study, said in a statement.

Researchers found variations in IGHV1-69, an immune system gene that controls the release of antibodies and helps fight the flu. They looked at blood samples from volunteers of African, Asian, and European descent, all of whom had received the vaccine for the H5N1 flu virus in 2007.

From there, they examined IGHV1-69 frequency, and found that the gene appeared in different numbers and variations in certain ethnic groups.

That’s an important finding, because some versions of the gene—it can appear in 14 different forms—are actually better at producing the antibodies needed to fight influenza than others. While everyone has some version of this gene, about 15 to 20 percent of the population has a version that isn’t able to produce the necessary antibodies at all. As a result, those individuals have a lower immune response to the vaccine, and thus may see decreased effectiveness. The DCFI study did not specify which ethnic groups were associated with lower flu vaccination effectiveness.

DCFI’s research could eventually be used to create a comprehensive map of all the gene variants and the populations they correspond to around the world, which could help illuminate which vaccines will be more useful for certain individuals.

The study “will be particularly important for the development and monitoring of the next-generation ‘universal’ influenza vaccines” in the future, the researchers wrote.