Flu vaccine effectiveness depends on your genes

An analysis of influenza vaccine response in more than 500 people has identified nine genes that influence the effectiveness of the treatment.

The research – which involved computational interrogation of 32,034 genes – confirms the findings of smaller studies, and helps to explain why the effectiveness of the flu vax tends to decrease in older people.

In a study published in the journal Science Immunology, scientists working under the banner of the Human Immunology Project Consortium (HIPC) at Yale University in the US say using big datasets to map the success of vaccinations “points to the prospect of predicting antibody responses before vaccination and provides insights into the biological mechanisms underlying successful vaccination responses”.

To make their findings the researchers used six of the HIPC’s vaccination cohorts, distributed across geographic locations and subject to different flu seasons. The groups comprised more than 500 people. In addition, blood samples taken before vaccination were available for 275 of them.

The data were examined to produce a set of all RNA traffic – known as transcriptions – to identify interactions that predicted flu vaccine responses.

These in turn were churned through a relatively new framework designed for quantifying information across multiple cohorts. The framework has previously been shown to produce robust results in the analysis of cancer data, and was first used in influenza research in 2014 when a team used it to predict a range of post-vaccination responses.

The new research set out to see if there was any genetic contribution that might throw light on why the standard trivalent (“three strain”) flu vax is less effective in older people.

Studies indicate that when the vaccine is given to older adults – although still under the age of 65 – it is only between 67% and 51% as effective as when it is given to younger people. Furthermore, in some older adults it fails to prompt any significant production of protective antibodies. A key meta-analysis conducted in 2012 concluded that there was insufficient reliable research to make a call on whether effectiveness continues to decline in people over the age of 65.

The HIPC team, led by Stefan Avey, identified nine genes strongly associated with vaccination response. All of the identified genes were associated with varying levels of antibody production.

Significantly, the genes were correlated with strong immune response in young people, but a generally poor one in older folk. The results remained robust after all confounding factors – such as age, lifestyle and smoker status – were taken into account.

The scientists suggest that the findings suggest the effectiveness of flu vaccines in older people might be able to be boosted by modifying their immune systems beforehand to prompt increased antibody activity.