There is a need for a new way of treating the disease. Covid-19 might not go away. It is still hospitalizing and killing people even in countries with high levels of immunity. Only a handful of effective treatments have been found, and these might not work against future versions.

The risk of getting seriously ill with covid-19 is raised by age, as is the risk of developing long covid. If these drugs work, the hope is that they can help treat that as well.

Younger defenses

The immune system is affected by age. Older people are more likely to die from the flu, and their immune systems don't respond as strongly to vaccines. Some immune cells are less able to kill harmful viruses. Others seem to be more easily triggered into action and maintain higher levels of damaging inflammation even when there is no infections.

Younger people who are biologically old are thought to have more of the same functions as older people. Diabetes, lung and heart diseases, are some of the conditions that make a person more vulnerable to the coronaviruses. People with a higher-than- expected biological age 10 years before the start of the epidemic were more likely to die.

One type of immune cell that appears to go awry in older people is the neutrophils. These cells are in our blood until an infection strikes, at which point they make a beeline for the area of the infection. The cells seem to stray off in the wrong direction in older people and can cause significant damage.

She and her team are working on a way to make neutrophils more efficient at targeting infections. The team has found that blocking the activity of an enzyme that influences how the immune system works can return neutrophils to a younger state in the lab. Lord found that drugs commonly prescribed to lower cholesterol might have a similar effect.

"Imagine if, in the pandemic, everyone had the immune system of a 20-year-old"

Kristen Fortney, cofounder and CEO of BioAge Labs

A few years ago, Lord and her colleagues ran a small clinical trial of a statin in people who were hospitalized with pneumonia. simvastatin was given to half of the volunteers. The blood tests showed that the people taking vastatin acted like cells from younger people and were better at targeting infections. Only a small percentage of those who took the statin did not die within 30 days of the trial.

Older immune systems might benefit from the approach if it works. There is evidence from China that shows a link between statin use and survival. Xiao-Jing Zhang and colleagues compared the outcomes of 13,981 people who were admitted to hospital with covid-19 in Hubei province, 1,219 of whom were taking statins. The team found that people who took vastatin were less likely to die.