Information that three researchers at a virus laboratory in Chinese Wuhan would have had covid-like symptoms already in November 2019 has given new impetus to the suspicions that the pandemic may have been started by a lab leak.

Chinese authorities have strongly denied the information. But US President Joe Biden recently instructed the country’s intelligence services to produce a report by the end of August. And although the WHO in March described a lab leak as “extremely unlikely”, Director-General Tedros Adhanom Ghebreyesus pointed out at the same time that the investigation had not been sufficiently thorough and that the issue needed to be further examined.

Studied dangerous viruses

It is well documented that the Wuhan Institute of Virology, as the laboratory is called, studied several types of potentially dangerous viruses from bats. According to Financial Times this was done with financial support from, among others, the USA. It was part of the international effort to acquire the necessary knowledge about these viruses, in order to prevent new epidemics following the outbreaks of SARS in 2003 and March 2012.

Part of the research was to investigate what type of changes in the genome are required for different bat viruses to be able to spread to humans. In that work, a group of American and Chinese researchers, for example, created a modified virus from the bat genus horse cone, which had the ability to bind to the very receptors in human airways that the new coronavirus sars-cov-2 now uses to spread.

By mixing this virus with a mouse virus, the researchers developed a virus that in test tube experiments could replicate itself in human cells, and which in animal experiments on mice proved to be able to infect and damage the lung tissue.

“Our work points to a potential risk of new outbreaks of sars-cov from viruses currently circulating in bat populations,” the researchers wrote when the study was published in the scientific journal Nature 2015.

“There is no evidence”

The Nature article was recently supplemented with an unusual comment from the editor: “We are aware that this study is being used as an argument for unverified theories that the new coronavirus causing covid-19 would be artificial. There is no evidence that it would be true; scientists believe an animal is the most likely source of this coronavirus. “

– It is definitely not about that they have tried to create a nasty virus, but is simply a routine way to study how bat viruses can take the leap over to other mammals and then also to humans. But you also wonder what has happened since this study in 2015, says Tomas Bergström, professor of clinical microbiology at the University of Gothenburg.

Together with his research group, he has his own experience of working with coronavirus in a security-classified laboratory. The water system and ventilation have been isolated from the outside world to cut off all possible routes of transmission, and each operation must be performed in exactly the right way, with the right protective equipment.

But despite all safety measures, there is always a risk of spreading the infection, he emphasizes. So it is not impossible to think that this is how the pandemic started in China. Or it turned out, just as the researchers warned in their article in 2015, that the virus came directly from the animal world.

Analyze the relationship

To get answers, descriptions of the viruses that were studied in the laboratory are required, so that it becomes possible to compare the genome with the coronavirus that is now found all over the world, Tomas Bergström explains. In addition, test results are needed from the three researchers who are suspected of having had covid-like symptoms even before the disease was known. Finally, more of the samples that are always saved from blood donors must be analyzed, in order to be able to search more broadly for antibodies further back in time.

With the help of these data, it is possible to analyze the relationship between the virus variants, in order to calculate if and if so how they are connected. For example, if it turns out that three people have been infected with a virus with the same gene sequence, it can be concluded that they were infected by the same source. And the more the gene sequence of the virus resembles an original virus, either from the laboratory or in nature, the earlier in the chain of infection the infection occurred.

Do not put anyone there

But so far it has been slow. WHO staff had only limited access to information when they carried out their on-site investigation earlier this spring.

– In a safety laboratory, it is routine to top everyone who becomes ill, so samples have been taken of these people. And of course, there must be detailed data on all the viruses they worked with in the lab. But there are holes in the investigation there, says Tomas Bergström.

– It is not about putting someone there, but about finding out what happened so that we can learn more and prevent new outbreaks. China has been part of the international research on coronavirus. Therefore, it is remarkable that you do not get the information needed now that it is sharp mode, he adds.