Again, we are talking about the source of SARS-CoV-2, the virus that causes COVID-19.
Initially, the US Department of Energy’s investigation placed more emphasis on laboratory leaks than before, although confidence in this was low.
The second, and most important, is the release and analysis this week of the virus and animal samples collected from the Huanan wet market in Wuhan, the place linked to the origin of the epidemic.
It’s a close lesson for me. I was the Australian delegate to the World Health Organization (WHO) international investigation into the origin of SARS-CoV-2. I went to Wuhan on a fact-finding mission in early 2021. I visited a closed market.
We now have strong evidence that places raccoon dogs on the market as animal reservoirs for SARS-CoV-2, which can be transmitted to humans.
The debate over the origin of the COVID-19 virus has been fierce. A report released today provides the strongest evidence to date of an animal origin, pointing to a particular animal – the racoon dog – and a specific place in the live animal market. @normanswan #abc730 pic.twitter.com/oiXII4SWTK
– abc730 (@abc730) March 21, 2023
If we had this evidence three years ago, we have to wonder how recent history would have turned out. We would have reduced the great power, the media frenzy and the political upheaval about the improbable origins of the epidemic. We can focus our attention on research.
Circles, circles, and puzzles
Samples were taken from different locations in the market, in January 2020, within a few weeks of the first cases of COVID-19 in Wuhan. SARS-CoV-2 RNA and human DNA were detected in these natural samples, although none of the animal swabs were infected with the virus.
This was presented to the WHO team investigating the outbreak in January 2021, which I was part of.
This work was published in print (posted online, before independent verification) in February 2022.
The “metagenomic” data confirming what was previously published – that SARS-CoV-2 and human (but not animal) systems were present – had to be provided to allow further analysis.
This is something that is often required in journals and is considered appropriate in the spirit of open science and collaboration.
However, it was not until early March 2023 that the world public discovered this.
That’s when there was a “drop” of natural metagenomic sequences in the GISAID database, the world’s open source for viruses.
This allowed an independent group of international experts to analyze it. In a startling revelation, they identified high levels of raccoon dog and other animal DNA in association with SARS-CoV-2.
Raccoon dogs can be infected with SARS-CoV-2 and can be contagious. The international group published what they saw as a press release earlier this week.
The most obvious was the combination of viruses and animals in the corner of the largest market, the corner related to the crimes of the first people. It is now known (but initially denied by the Chinese authorities) that wild and domesticated animals were sold in this area of the market.
After the results were analyzed by an international team, Chinese scientists who tested the market were contacted for clarification and discussion – especially for the analysis that was mixed between SARS-CoV-2 and a large part of raccoon dogs. DNA of other animals.
The results were removed from the GISAID database within hours of the study authors being accessed. This is probably not unusual for an open source database like GISAID, and an explanation may be sought as to why this happened.
Why is this work important?
This recent work does not prove that raccoon dogs were indeed the source of SARS-CoV-2. Apparently, they must have been an intermediate group between bats and humans. Bats harbor many coronaviruses, including those related to SARS-CoV-2.
However, the same applies to the case of animal/human contacts of SARS-CoV-2.
This, as well as other evaluations of animal links to SARS-CoV-2, should be considered due to the lack of hard data to support other theories of the origin of SARS-CoV-2, such as laboratory leaks, contaminated food, and purchases from outside China. Little by little, the evidence is consistent with the origin of these animals, which were concentrated in the Huanan market in Wuhan.
The length of time taken for this preliminary work to appear and the difficulty in obtaining raw data are regrettable, points made recently by the WHO.
Mercifully, one might say, a faulty analysis of the data collected in early 2020 was done and the researchers missed the animal links.
Cynically, (and without evidence) one could say that the need for data was recognized, but not readily available. This is a question for Chinese researchers at the China Center for Disease Control to answer.
What are the consequences of this delay?
This would have been known in early 2020 so that additional studies to understand the origin of the virus in animals would have been done.
Three years on, it is very difficult to conduct such studies, tracing back from the now closed market to the sources of the animals and the people who caught them.
Clear answers would have taken the heat out of the debate about how viruses start. Of course, all speculation should still be on the table, but some of this could have been better explored with previous events.
Would it have changed the course of the epidemic? Maybe not. The problem had already spread around the world and was well adapted to human spread by the time the project was discovered. However, it could lead to better research and better planning for future outbreaks.
What now?
What we are learning about the future is clear. Public disclosure of data sequences is the best way to conduct scientific research, especially on something of global importance.
Making data unavailable, or not needing help with critical analysis, only slows down the process.
The political consequences of both countries, especially the US and China, have caused suspicion to increase, and progress has slowed significantly.
Although the WHO has been criticized for mistakes in its handling of the epidemic, and for combining data to understand the origins and advance future research, it remains the best international organization to encourage open data sharing.
Scientists, in particular, want to do the right thing and find answers to the most important questions. Controlling this is important.
Dominic Dwyer, Director of Public Health Pathology, NSW Health Pathology, Westmead Hospital and University of Sydney, University of Sydney
This article is reprinted from The Conversation under a Creative Commons license. Read the first article.
