New flu jabs will offer better protection for the elderly
BETTER flu jabs could be on the horizon after a breakthrough by scientists.
Older people do not produce enough antibodies to protect against new strains of the virus, according to new research.
It may explain why vaccines sometimes do not work – especially in the elderly.
Senior study author Dr Patrick Wilson, of the University of Chicago in the US, 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.”
The jab contains tiny doses of certain flu strains which change each year.
The idea is to trigger antibodies that fight the viruses. It won’t give you flu, but without the right antibodies – secreted by the immune systems B cells – it won’t protect you either.
Dr Wilson and colleagues have shown the blood proteins that fight foreign invaders are less diverse in older individuals.
This means the vaccine is more likely to fail by not fuelling antibodies that will combat current strains.
The US team said their B cells are less capable of making antibodies that can adapt to new viral strains.
Over time, they acquire fewer mutations to make them flexible enough against the ever-changing flu virus.
The detrimental effect of ageing on the immune system is thought to be a major cause of illness and death in the elderly by increasing susceptibility to bacterial, fungal and viral infections.
Most flu deaths occur among the over 65s who have a significantly reduced antibody response to the jab.
This is why it is a major killer for the elderly, with the vaccine protecting only a fraction of them.
The study, published in the journal Cell Host and Microbe, compared how B cells and antibodies from elderly and younger adults respond to vaccination with different flu. While B cells from younger subjects showed a continued recent accumulation of mutations, the elderly appeared to have an essentially fixed repertoire.
They lacked recent adaptations that would allow the evolution of B cells to divergent flu strains.
What is more antibodies from the elderly are less potent and less capable of protecting against the virus, said Dr Wilson. They can only target old strains, with fewer variants that would enable effective responses against evolving versions.
Dr Wilson: “More recent vaccines developed especially for the elderly population are now on the market and could help induce more protective antibodies.”