A genetic variant in a specific gene influences the response to the influenza vaccine, according to a new study.

The researchers found that individuals who had at least one copy of the minor allele were more likely to achieve seroconversion (i.e. have detectable antibodies against the particular influenza strain) after vaccination. The difference was particularly pronounced for people on high doses of immune-suppressant drugs. To understand how the different alleles influence the immune response to vaccination, the researchers next looked in more detail at immune cells from 47 of the patients (34 had two major T alleles, and 13 had at least one minor G allele).