Most middle aged adults could benefit from a short term treatment to revitalise the immune system and organs that deteriorate with age, say researchers

Scientists have hailed the success of a clinical trial which found that experimental anti-ageing drugs may protect older people from potentially fatal respiratory infections by rejuvenating their immune systems.

In a trial involving people aged 65 and over, those who received a combination therapy of two anti-ageing compounds reported nearly half the number of infections over the following year as a control group who received only placebos.

The experimental drugs, known as mTOR inhibitors, also appeared to boost people’s responses to the flu vaccine, with tests revealing 20% more flu-fighting antibodies in the blood a month after the vaccination was given.

The findings are a milestone for researchers who believe that the best way to tackle diseases of old age may be to design new drugs that combat the ageing process itself.

“Immune function was just one of the things that got better,” said Joan Mannick, who worked on the trial at Novartis Institutes for Biomedical Research in Massachusetts. The researchers now have plans to test the drugs on other age-related conditions, such as neurodegenerative diseases.

“This is an extremely important and exciting study,” said Matt Kaeberlein, director of the Healthy Aging and Longevity Research Institute at the University of Washington, who was not involved in the study. The mTOR inhibitors “appear to broadly rejuvenate immune function in healthy elderly people,” he added. “I think this study raises the real possibility that most middle-aged adults could benefit from short-term treatments with mTOR inhibitors.”

The drugs work by blocking a cascade of events in the body that starts with the so-called “mechanistic target of rapamycin”, or mTOR. This is one of a group of proteins involved in the ageing process. Tests in mice have shown that experimental mTOR inhibitors can extend lifespan and revitalise the immune system and organs which deteriorate in old age.

The six week trial investigated the effects of two different mTOR inhibitors. The 264 volunteers who took part received one or both of the drugs, or joined a control group that was given only placebos. All were then monitored for a year to see how their immune systems reacted, and how many respiratory infections they picked up. Those who had low doses of both drugs reported an average of 1.49 infections per year, compared with 2.41 in the placebo group.

As people grow older, their immune systems weaken and they become increasingly vulnerable to infections and less able to generate the strong responses that vaccinations need to trigger to work well.

If drugs can be found that boost the immune systems of older people, they could help to protect the whole population from infections. “In the future, a larger percentage of our population is going to be older,” said Deborah Dunn-Walters, a professor of immunology at the University of Surrey who was not involved in the study. “If older people don’t respond well to vaccinations, then there will be more and more people that aren’t protected and who can potentially pass on infections to others in the population.”

“It is promising for the future that you can actually give these drugs at a very low dose which is not toxic and still seems to have a significant effect in protecting older people,” she added. Respiratory tract infections are one of the leading causes of death in older people and are largely responsible for the extreme burden on the NHS in the winter months.



Mannick, who is now chief medical officer at a Boston-based company called resTORbio, found that the drugs boosted immune responses that specifically target viruses. Details of the trial are published in the journal Science Translational Medicine.

The next stage of the research will look at whether the drugs work better in some groups of older people than others, for example the over-85s or those with conditions such as asthma, diabetes or heart failure.

“We hope we can keep everybody healthier and with a better quality of life as they grow older,” Mannick said.