Why the elderly are more susceptible to flu revealed

We’re deep into flu season and if you have elderly relatives then you are likely to be concerned that they could be struck down. But why are the over-65s so susceptible to influenza when we know that the immune system becomes stronger over time as it is exposed to viruses?

This is a question that has never been fully answered before, but now, a team at the University of Chicago has made a breakthrough that could help to pave the way for better flu vaccines for the elderly.

As we all know, theory suggests that the more flu an individual is exposed to, the better at recognising it the immune system becomes. This puts our bodies on the defensive and more able to attack the virus when it is present.

Data consistently shows, however, that the elderly are more likely to die of flu than any other demographic. That includes young children who have never been exposed to the virus in the past. This therefore flies in the face of all that has been known about the immune system for decades.

Now, scientists in Chicago have found that the issue does not lie in the body recognising viral enemies, but in the amount of antibodies it can produce in older age. It’s all to do with the B cells, which are responsible for creating the antibodies to fight new mutations.

The key observation made by the researchers when looking at these cells in people of all ages, was that those of younger people were more complex. This allows them to identify more mutations and produce a wider range of antibodies to combat them.

What was seen in older subjects was limited B cells and less potent antibodies. Memories from B cells created in earlier life were still present, but they had become outdated, with the inability to produce new ones. This more pared-down toolkit means they could only protect themselves against old strains of the flu, which is a major problem, as it is always evolving.

Dr Patrick Wilson, senior author of a new study that sheds some light on the issue, said: “The major implication is when a newly circulating influenza virus infects elderly individuals, they don't have quite the right tool to fight it because their antibodies are not as protective.

“Our findings could be used by the vaccine community to make better vaccines and improve protection of the elderly population.”

Despite the fact that there are already flu vaccines designed specifically for the over-50s and over-65s, the team in Chicago believe these could be greatly improved. Using their research as a base, they think that introducing more protective mutations into B cells could be the answer.

As well as vaccinating against flu, there are a number of precautions the elderly can take to reduce their chances of getting the virus. They include washing hands regularly with warm water and soap, and catching germs in tissues and disposing of them straight away.