Analysis

WASHINGTON — A report commissioned by federal regulators overseeing the nation’s commodities markets has concluded that climate change threatens U.S. financial markets, as the costs of wildfires, storms, droughts and floods spread through insurance and mortgage markets, pension funds and other financial institutions.

Covid-19 patients who are 80 or older are hundreds of times more likely to die than those under 40.

That’s partly because they are more likely to have underlying conditions — like diabetes and lung disease — that seem to make the body more vulnerable to Covid-19.

But some scientists suggest another likely, if underappreciated, driver of this increased risk: the aging immune system.

The changes that ripple through our network of immune cells as the decades pass are complex, resulting in an overreaction here, a delayed response there and over all, a strangely altered landscape of immunity.

Scientists who study the aging immune system say that understanding it may lead not only to a clearer sense of how age is connected to disease vulnerability, but to better strategies for vaccines and treatments for Covid-19.