Rob Stein

Alphonso Evans rolls his wheelchair into a weight machine in the gym at the Charlie Norwood VA Medical Center in Augusta, Ga.

"I'm not so much worried about dying from a heart attack or diabetes, because I'm active. I know what to do to work against it: watch what I eat, exercise," Evans says. "But what do I do about an infection? Or fighting off a bacteria — something inside me that I don't see until it's too late?"

For the first time, scientists have used genetically modified viruses to treat a patient fighting an antibiotic-resistant infection.

Isabelle Carnell-Holdaway, 17, began the experimental treatment after doctors lost all hope. She was struggling with a life-threatening infection after a lung transplant. With the new treatment, she has not been completely cured. But the Faversham, England, teenager has recovered so much that she has resumed a near-normal life.

The powerful gene-editing technique called CRISPR has been in the news a lot. And not all the news has been good: A Chinese scientist stunned the world last year when he announced he had used CRISPR to create genetically modified babies.

A group of prominent scientists and bioethicists is calling for a global moratorium on any new attempts to bring gene-edited babies into the world.

"We call for a global moratorium on all clinical uses of human germline editing — that is, changing heritable DNA (in sperm, eggs or embryos) to make genetically modified children," the 18 scientists and bioethicists from seven countries write in an article published Wednesday by the journal Nature.

Instead of eating a typical breakfast every day, Jonah Reeder gulps down a special protein shake.

"The nutrients in it like to sit at the bottom, so I usually have to shake it up and get all the nutrients from the protein and everything," says Reeder, 21, of Farmington, Utah, as he shakes a big plastic bottle.

There's strong new evidence that a common childhood vaccine is safe.

A large study released Monday finds no evidence that the vaccine that protects against measles, mumps and rubella increases the risk of autism. The study of children born in Denmark is one of the largest ever of the MMR vaccine.

In February, scientists started releasing genetically engineered mosquitoes in a high-security laboratory in Terni, Italy.

NPR was the only news organization allowed into the lab to witness the first releases. Correspondent Rob Stein reported on the start of the experiment: "Scientists Release Controversial Genetically Modified Mosquitoes In High-Security Lab."

Scientists have launched a major new phase in the testing of a controversial genetically modified organism: a mosquito designed to quickly spread a genetic mutation lethal to its own species, NPR has learned.

For the first time, researchers have begun large-scale releases of the engineered insects, into a high-security laboratory in Terni, Italy.

"This will really be a breakthrough experiment," says Ruth Mueller, an entomologist who runs the lab. "It's a historic moment."

The World Health Organization Thursday announced the formation of an international committee aimed at establishing uniform guidelines for editing human DNA in ways that can be passed down to future generations.

The 18-member committee "will examine the scientific, ethical, social and legal challenges associated with human genome editing," according to the WHO announcement.