Next step in the fight against the new crown: Global laboratories try to analyze live virus samples

Scientists need live virus samples to explore the biological mechanisms of new coronavirus infections and develop detection methods, drugs and vaccines. There is no indication that the outbreak of the new coronavirus is easing. Virologists around the world are eager for a physical sample of the virus. They are planning to test drugs and vaccines, develop models of animal infections, and study biological issues about the virus, such as how it spreads.

Next step in the fight against the new crown: Global laboratories try to analyze live virus samples

Source: Dr Linda Stannard/UCT/Science Photo Library

“The moment we learned of the outbreak, we began sending sample checkers to get these virus isolates. Vincent Munster, a virologist at the National Institute of Allergy and Infectious Diseases (NIAID), said. His lab is expected to get samples from the U.S. Centers for Disease Control and Prevention (CDC) next week. The CDC is responsible for leading the response to new cases of coronavirus infection in the United States.

The first laboratory to isolate and study a new type of coronavirus (temporarily known as “2019-nCoV”) came from Wuhan, China, the epicenter of the outbreak. A team led by Shi Zhengli, a virologist at the Wuhan Virus Research Institute, isolated the virus from a 49-year-old woman. The woman developed symptoms on 23 December 2019 and has since been in critical condition. Shi Zhengli’s team found that the new coronavirus uses a molecular receptor to enter and kill cultured human cells, which are the same as those used by SARS coronaviruses.

On January 28th an Australian laboratory announced that it had isolated samples of the virus from an infected person returning from China and was now preparing to share it with other scientists. Laboratories in France, Germany and Hong Kong are also isolating samples of the virus they take from local patients and sharing them publicly with their peers, said Bart Haagmans, a virologist at Erasmus Medical Center in Rotterdam, the Netherlands. “Maybe next week we’ll get the virus isolate from other labs, ” he said. “

Sequences and samples

Since the first genome sequence of the new coronavirus was released in early January, dozens of sequences have been released so far (from different populations). These sequences have helped to detect the virus and help study the spread and evolution of the pathogen. But scientists say genome sequences are not a substitute for viral samples, which are essential for drug and vaccine testing, as well as for in-depth studies of the virus. “Sharing samples of the virus is critical,” said Maria Van Kerkhove, an infectious disease epidemiologist at the World Health Organization, on January 29. “

Munster says his lab’s first task is to identify animals that are similar to the way humans are infected with the new coronavirus. Such animal models can be used to test the effectiveness of vaccines and drugs. The team first planned to study a mouse that had been genetically engineered to contain human receptors used by SARS virus and the new coronavirus to infect cells. He added that the next step may also be to test whether the vaccine can prevent infection by exposing mice, including subsequent non-human primates, to the new coronavirus.

Munster’s lab also hopes to assess how long the new coronavirus will survive in the air or saliva as soon as possible. This helps epidemiologists understand whether the virus can be transmitted through air or only through close contact. Munster’s research will use a container called “Goldberg drum” to atomize virus particles and then allow them to stay in the air for a period of time to measure their ability to infect human cells.

Such experiments will be conducted under strict isolation measures, i.e. to meet the biosafety level III standard to prevent infection of laboratory staff and to avoid accidental leakage of pathogens. There are thousands of such laboratories around the world, but Munster points out that many studies of the virus do not have to be conducted under such strict biosecurity conditions to speed up research.

Tracking the spread of the virus

One of Haagmans’ first tasks is to develop a blood test to examine antibodies to the new coronavirus. Such tests can identify people who have been exposed to 2019-nCoV but are no longer infected and may never develop symptoms.

His team also wanted to know whether ferrets could be used as a model for human infection. Researchers used animals to study influenza and other respiratory diseases because their lungs are similar in physiology to humans and are susceptible to certain of the same viruses. Haagmans wanted to test whether the new coronavirus could spread between these animals in order to get clues about human-to-human transmission.

Many of the 2019-nCoV-related issues that virologists plan to study are based on findings from previous studies of SARS and MERS viruses. For example, there are indications that a protein needed for SARS-infected cells has developed adaptations that make it easier to enter human cells.

Haagmans is still trying to get his first virus sample, but he hopes to get a few more samples as the outbreak progresses, tracking whether and how the new coronavirus has evolved. “We need to have a better understanding of the biological characteristics of the new coronaviruses, especially to find out how they differ from known viruses, ” he said. ” “

References:

1. Zhou, P. et al. Preprint at bioRxiv https://doi.org/10.1101/2020.01.22.914952 (2020).

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Originally published as China coronavirus: labs worldwide to live samples published on 31 January 2020

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Nature:doi:10.1038/d41586-020-00262-7