Current Affairs Topics: Knowing about the origins of COVID-19

Knowing about the origin of COVID-19

Recently, a group of 18 scientists, most of them from the U.S published a letter in the journal Science, calling for further investigation to determine the origin of the COVID­-19 pandemic.
The origin of SARS-CoV-2 or COVID-19 virus still remains a mystery. There is no clear information about where, when and how did the virus that causes the disease originate.
The novel coronavirus was first reported from Wuhan, a Chinese city hosting a laboratory conducting virus research, and the Program for Monitoring Emerging Diseases (ProMED) notified pneumonia of unknown cause in the city on December 30, 2019. The city’s Huanan wet market was associated with many of the earliest cases.

The two prevailing competing theories about the origin of the Virus:

• Natural spillover theory: The virus jumped from animals, possibly originating with bats, to humans, or
• Lab leak theory: The virus escaped from a virology laboratory in Wuhan, China.

WHO’s governing forum, the World Health Assembly, mandated the Director-­General in May 2020 to conduct an inquiry into the origin of SARS­-CoV­2, and a joint probe was carried out by WHO and China in January-February 2021.

• Since there was no conclusive evidence for either hypothesis — natural spillover or lab leak — there were apprehensions when the report leaned in favour of the animal origin hypothesis, describing it as “likely to very likely”, and stated that a laboratory incident was “extremely unlikely”.
• Many did not see the investigation as being extensive enough and experts view that the more studies were necessary.
• Experts are concerned that the lab leak possibility had been given inadequate attention by the WHO team, and, in fact, treated as a “conspiracy theory”. Understanding the origin of the virus was important to both increase safety in laboratories undertaking biological research, and to prevent pandemics of animal origin.

Why is the lab in Wuhan a focus on interest?

• The Wuhan Institute of Virology (WIV) is a high-security research facility that studies pathogens in nature with the potential to infect humans with deadly and exotic new diseases. The lab has done extensive work on bat-borne viruses since the 2002 SARS-CoV-1 international outbreak, which began in China.
• The search for its origins led years later to discovery of SARS-like viruses in a southwest China bat cave. The institute collects genetic material from wildlife for experimentation at its Wuhan lab.
• Researchers experiment with live viruses in animals to gauge human susceptibility. To reduce the risk of pathogens escaping accidentally, the facility is supposed to enforce rigorous safety protocols, such as protective garb and super air filtration. But even the strictest measures cannot eliminate such risks.

Arguments in favour of Wuhan lab leak theory:

• To some scientists, the release of a dangerous pathogen via a careless lab worker is a plausible hypothesis for how the pandemic started and warrants investigation.
• The Wuhan lab, China’s leading SARS research facility, is not far from the Huanan Seafood Market, which early in the health crisis was cited as the most likely place where animal-to-human transmission of the virus may have taken place. The market was also the site of the first known COVID-19 superspreader event.
• The suspicions is mainly based on following facts:
  • Proximity between Wuhan lab and Huanan Seafood Market,
  • The failure so far to identify any wildlife infected with the same viral lineage,
  • Chinese government’s refusal to allow the lab-leak scenario to be fully investigated.
• Although the Wuhan lab’s scientists have said they had no trace of SARS-CoV-2 in their inventory at the time, 24 researchers sent a letter to the World Health Organization (WHO) urging a rigorous, independent investigation. The WHO’s first such mission to China this year failed to probe deeply enough, they wrote.
• A U.S. State Department fact sheet, released before the WHO mission alleged, without proof, that several WIV researchers had fallen sick with symptoms consistent with COVID-19 or common seasonal illnesses before the first publicly confirmed case in December 2019.
• A May 5, story by Nicholas Wade in the Bulletin of the Atomic Scientists, said lab scientists experimenting on a virus sometimes insert a sequence called a “furin cleavage site” into its genome in a manner that makes the virus more infective.
  • David Baltimore, a Nobel Prize-winning virologist quoted in the article, said when he spotted the sequence in the SARS-CoV-2 genome, he felt he had found the smoking gun for the origin of the virus.
  • The novel corona virus is less similar, by comparison, to the genome of viruses that have caused other epidemics such as SARS (severe acute respiratory syndrome) and MERS (Middle East respiratory syndrome).

Arguments for animal-to-human transmission (Natural spillover theory):

• Many scientists believe a natural origin is more likely and have seen no scientific evidence to support the lab leak theory.
• The Joint WHO­-China study report identifies a SARS­ related coronavirus in a bat to which the SARS-­CoV­2 virus has 96.2% genomic similarity.
• Another scientist K. G. Andersen, who has done extensive work on corona viruses, Ebola and other pathogens transmissible from animals to humans, said similar genomic sequences occur naturally in coronaviruses and are unlikely to be manipulated in the way Baltimore described for experimentation.
• Scientists who favor the natural origins hypothesis have relied largely on history. Some of the most lethal new diseases of the past century have been traced to human interactions with wildlife and domestic animals, including the first SARS epidemic (bats), MERS-CoV (camels), Ebola (bats or non-human primates) and Nipah virus.
• While an animal source has not been identified so far, swabs of stalls in the wildlife section of the wildlife market in Wuhan after the outbreak tested positive, suggesting an infected animal or human handler.

Thus both the theories lacks definitive proof.
On May 26, U.S. President said his national security staff does not believe there is sufficient information to assess one theory to be more likely than the other. He instructed intelligence officials to collect and analyze information that could close in on definitive conclusion and report back in 90 days.
The Director-­General of the World Health Organization (WHO), Tedros Adhanom Ghebreyesus, has also acknowledged that more work needs to be done on the lab leak theory, although a WHO team that visited Wuhan thought a leak to be the least likely hypothesis.