Specific gene variant may influence effectiveness of flu vaccine, study finds


Specific gene variant may influence effectiveness of flu vaccine, study finds

According to the Centers for Disease Control and Prevention, flu season is here. In line with National Influenza Vaccination Week from December 7th-13th, the organization is encouraging everyone over the age of 6 months to get the annual flu vaccine. But a new study finds that a variant in a gene called IL-28B may influence the effectiveness of the vaccine.

A variant in the IL-28B gene may influence the immune system's response to the annual flu vaccine, according to researchers.

The research team - including Adrian Egli from the University of Basel in Switzerland - publish their findings in the journal PLOS Pathogens.

Although most individuals with flu experience mild illness, the virus can cause complications - including pneumonia, bronchitis and sinus infections - among elderly individuals, pregnant women and those with weakened immune systems. Such complications may lead to hospitalization and even death.

While the annual flu vaccine is recommended for everyone aged 6 months and older, populations at high risk of flu-related complications are prioritized for vaccination. But the research team notes that among such populations, the flu vaccine can often be ineffective.

Past studies have suggested that different versions, or alleles, of the IL-28B gene may affect an individual's immune response to the vaccine.

To find out more, Egli and colleagues assessed the blood samples of 196 patients who underwent organ transplantation and who were part of a clinical trial investigating the effectiveness of the flu vaccine. Vaccines tend to be ineffective in such patients, the researchers note, as their immune system has been weakened by immunosuppressant drugs administered to prevent organ rejection.

Minor G allele suppresses IL-28B gene expression, boosts immune response

From the blood samples, the team identified the alleles present in the IL-28B genes of each patient. Each individual has two copies of IL-28B.

Two copies of the major T allele were identified among 135 patients, 54 patients had one copy of the major T allele and one copy of the minor G allele, while seven patients had two copies of the minor G allele.

The team found that after receiving the flu vaccination, patients who possessed at least one copy of the minor G allele were more likely to have seroconversion - detectable antibodies against the influenza virus in their blood - compared with patients who possessed other alleles.

The researchers then set out to determine how specific alleles affect a patient's immune response to the flu vaccine. To do this, they analyzed the immune cells of 47 of the patients, of which 34 had two copies of the major T allele and 13 had at least one copy of the minor G allele.

The results of the analysis revealed that patients who had at least one minor G allele demonstrated a stronger immune response to the influenza vaccination. In detail, they found that the minor G allele appeared to reduce IL-28B gene expression and increase IL-4 production in T cells and B cells. Adding more IL-28B to carriers of minor G alleles appeared to make these alleles act like major T alleles, which reduced the immune response to the flu vaccine.

Inhibiting IL-28B receptor could boost immune response to flu vaccine

The team then set out to determine whether these findings could be seen among healthy patients who received the flu vaccine. They did this by analyzing the blood samples of 28 healthy people who had two copies of the major T alleles and 21 who had at least one copy of the minor G allele.

The researchers found that healthy individuals who possessed at least one copy of the minor G allele showed reduced IL-28B gene expression and a stronger immune response to the flu vaccine, compared with those who had two copies of the major T allele.

By introducing a molecule that blocks the IL-28B receptor to the immune cells of people who carried two copies of the major T alleles, the team found it boosted immune response.

Commenting on this finding, the researchers say:

Peptides used to inhibit [IL-28B receptor] signaling may play a role in augmenting vaccine responses and as such, represents a novel avenue for developing new adjuvants.

Further studies in other populations such as other immunosuppressed populations, elderly persons and healthy individuals would also lead to improved vaccine strategies."

Medical-Diag.com recently reported on a warning from the Centers for Disease Control and Prevention (CDC) that this year's flu season may incorporate strains of flu virus that are not covered by the annual flu vaccine.

However, the CDC state that this should not discourage people from getting the vaccine, particularly those who are at high risk of flu-related complications.

Toward a Universal Influenza Virus Vaccine (Video Medical And Professional 2020).

Section Issues On Medicine: Disease