Virus World

Emmanuelle Charpentier and Jennifer A. Doudna developed the Crispr tool, which can change the DNA of animals, plants and microorganisms with high precision.  The Nobel Prize in Chemistry was jointly awarded on Wednesday to Emmanuelle Charpentier and Jennifer A. Doudna for their 2012 work on Crispr-Cas9, a method to edit DNA. The announcement marks the first time the award has gone to two women. “This year’s prize is about rewriting the code of life,” Goran K. Hansson, the secretary-general of the Royal Swedish Academy of Sciences, said as he announced the names of the laureates. Dr. Charpentier and Dr. Doudna, only the sixth and seventh women in history to win a chemistry prize, did much of the pioneering work to turn molecules made by microbes into a tool for customizing genes — whether in microbes, plants, animals or even humans.“I’m over the moon, I’m in shock,” Dr. Doudna, a professor at the University of California, Berkeley, said at a news conference on Wednesday. It has been only eight years since Dr. Doudna and Dr. Charpentier — now the director of the Max Planck Unit for the Science of Pathogens in Berlin — co-authored their first paper demonstrating the power of Crispr-Cas9. Since then, the technology has exploded. Doctors are testing it as a cure for genetic disorders such as sickle cell disease and hereditary blindness. Plant scientists are using it to create new crops. Some researchers are even trying to use Crispr to bring species back from extinction.

Harvey Alter, Michael Houghton and Charles Rice share the award for research on a virus that causes hundreds of thousands of deaths a year. A trio of scientists who identified and characterized the virus responsible for many cases of hepatitis and liver disease — hepatitis C — are the recipients of the 2020 Nobel Prize in Physiology or Medicine. The winners are Harvey Alter at the US National Institutes of Health in Bethesda, Maryland; Michael Houghton, now at the University of Alberta in Canada; and Charles Rice, now at Rockefeller University in New York City. Their work on the hepatitis C virus paved the way for effective treatments against the infection that are now available. The World Health Organization (WHO) estimates that 71 million people worldwide are chronically infected with hepatitis C, which causes nearly 400,000 deaths per year, mostly from cirrhosis and liver cancer. The prize is well deserved, says Ellie Barnes, who studies liver medicine and immunology at the University of Oxford, UK. “It stands out as an emblem of great science,” she says. “We’ve got to a point where we can cure most people who are infected.” The prizewinners will share an award of 10 million kronor (US$1.1 million).

Blood-borne pathogen

In the 1970s, Alter studied the transmission of hepatitis, or liver inflammation, as a result of blood transfusions. Earlier work had identified hepatitis A and B viruses, but Alter showed that a third, blood-borne viral pathogen could transmit the disease to chimpanzees. Houghton, then working at Chiron Corporation in Emeryville, California, and his colleagues identified the virus on the basis of genetic material from infected chimpanzees, showing that it was a new kind of RNA virus that belonged to the Flavivirus family. They named it hepatitis C virus. 

A team led by Rice, then based at Washington University in St. Louis, Missouri, used genetic-engineering techniques to characterize a portion of the hepatitis C genome responsible for viral replication, demonstrating its role in causing liver disease. Some researchers had considered virologist Ralf Bartenschlager at the University of Heidelberg a candidate for a Nobel prize for hepatitis C, for his research into ways to propagate the pathogen in the laboratory. But Bartenschlagerhe says that the Nobel committee made a reasonable choice. “It’s a really difficult decision,” he says. “I think the way they have approached it is fairly well understandable.” In the past, Houghton has been vocal critic of scientific prizes that limit the number of recipients; the maximum number of awardees for a single Nobel prize is three. In 2013, he declined a prestigious Canada Gairdner Award — which came with a $100,000 prize — because the award did not recognize his collaborators Qui-Lim Choo and George Kuo at Chiron. “He always wants to see his discovery as a team approach,” says Thomas Baumert, a virologist and hepatologist at the University of Strasbourg in France.

Vaccine difficulties

The result of research by the prizewinners and others has led to significant improvements in hepatitis testing and treatment. In the past decade, harsh and poorly effective treatments for the infection have been replaced by drugs that directly block the virus. These medicines have the potential to cure the vast majority of hepatitis C infections, but their high cost has limited access in many low- and middle-income countries. Treatment requires following a drug regimen for 8–12 weeks, says Barnes. “Many of the people living with hepatitis C remain in vulnerable settings or are i.v. drug users, where it’s actually quite hard to get the drugs to the people affected.”  Bartenschlager says that he hopes that the Nobel will bring attention to the “silent epidemic” of hepatitis C around the world. The WHO has set a goal of eradicating the hepatitis C virus by 2030, which Barnes says could be achievable. But to do so, she adds, might require a vaccine.