More than six years after Covid-19 first emerged, one question still has no definitive answer: Where did the virus come from?
The debate has resurfaced after the US Central Intelligence Agency (CIA) assessed that a research-related origin is more likely than a natural one.
However, it stressed that the conclusion carries “low confidence” because the available evidence remains incomplete and inconclusive.
The renewed debate comes at a time when Covid has largely faded from daily life but continues to claim lives and occasionally cause local outbreaks.
Scientists say discovering the virus’s origin is not just about assigning blame; it is about preventing the next pandemic.
Why is Covid-19’s origin still a mystery?
Unlike previous disease outbreaks, investigators have never been able to identify the exact animal that first transmitted SARS-CoV-2 to humans.
At the same time, no publicly available evidence has conclusively proved that the virus escaped from a laboratory.
The first known cluster of infections was detected in Wuhan, China, in December 2019. However, scientists believe the virus may have been circulating weeks before the outbreak was officially identified.
The lack of complete access to early patient records, wildlife samples and laboratory data has made it difficult to reach a final conclusion.
In its 2025 report, the World Health Organisation’s Scientific Advisory Group (SAGO) said all hypotheses, including natural spillover and a laboratory incident, remain on the table because crucial information is still unavailable.
Recent deaths in India due to Covid
Although Covid-19 is no longer a global public health emergency, isolated infections and deaths continue to be reported in India, mainly among elderly people and those with underlying health conditions.
Andhra Pradesh
- Between 26 June and 16 July 2026, the state reported 12 Covid-19 cases and four deaths.
- Three deaths were reported from Kadapa and one from Kakinada. Health officials said all four patients had serious underlying illnesses.
- The state’s total case count later increased to 49, while the death toll remained at four.
Kolkata
- 80-year-old Subir Kar died after testing positive for Covid, becoming the city’s fourth Covid-related death in 26 days.
- Officials said he had underlying health conditions. A 10-year-old boy also tested positive and was admitted to hospital in stable condition.
- Health experts say most recent infections are linked to Omicron sub-variants and are generally mild.
- They continue to recommend vaccination for high-risk groups and early testing for vulnerable patients.
Two theories behind the pandemic’s beginning
Scientists and intelligence agencies continue to examine two main explanations.
1. Natural spillover
- This theory suggests the virus moved naturally from animals to humans, possibly through an intermediate host sold in wildlife markets.
- Supporters note that previous coronavirus outbreaks, including SARS and MERS, also crossed from animals to humans.
- WHO says this remains the explanation with the strongest scientific support based on currently available evidence, although it is not proven.
2. Laboratory-related incident
- The second theory argues that the virus accidentally escaped during research at a laboratory in Wuhan.
- Supporters point to the Wuhan Institute of Virology, which studies bat coronaviruses, and argue that a laboratory accident cannot be ruled out.
- However, no publicly available evidence has conclusively demonstrated that such a leak occurred.
How did CIA assessment bring back lab leak debate?
The CIA recently revised its assessment, saying a research-related origin appears more likely than a natural origin, while making clear that its judgment is based on low confidence.
In intelligence terminology, “low confidence” means the available information is limited, contradictory or insufficient to reach a firm conclusion.
Officials have also said the updated assessment was not based on newly discovered intelligence, but on a fresh review of existing material.
The announcement has renewed global debate because different US agencies have reached different conclusions over the years, while some continue to remain undecided.
Why is Wuhan laboratory at centre of controversy?
The Wuhan Institute of Virology is one of China’s leading research centres studying bat coronaviruses.
Its location in the same city where the first Covid outbreak was detected has made it central to the lab leak debate.
Supporters of the laboratory-origin theory argue that the coincidence deserves deeper investigation.
Others caution that proximity alone is not evidence and that Wuhan is a major transport and research hub with millions of residents.
China has repeatedly rejected allegations of a laboratory leak, calling them politically motivated.
Why has Anthony Fauci become a key figure in debate?
Former US infectious disease expert Anthony Fauci became one of the best-known public health officials during the pandemic.
Republican lawmakers have repeatedly questioned him over government funding for coronavirus research, early pandemic decisions and his public statements on Covid’s origin.
During a recent Senate hearing, Fauci invoked the Fifth Amendment and declined to answer many questions on legal advice.
Under US law, invoking the Fifth Amendment protects individuals from being compelled to give testimony that could later be used against them. It is not considered an admission of guilt.
The hearing has further intensified political debate over how the pandemic was handled in the United States.
What do scientists and global agencies say?
- WHO says there is still no conclusive evidence supporting either theory.
- Many scientists continue to favour natural spillover based on existing evidence.
- Others believe a laboratory accident cannot yet be ruled out.
- Experts agree more data from the early outbreak is needed.
Why is there still no final answer on Covid’s origin?
The biggest obstacle is the lack of complete evidence.
Key records from the earliest days of the outbreak remain unavailable, while several years have passed since the virus first emerged.
As time passes, tracing its exact path becomes increasingly difficult.
For now, the origin of Covid-19 remains one of modern science’s biggest unanswered questions.
Whether the virus emerged naturally or through a research-related incident, experts agree that understanding its origin is essential to improving global disease surveillance, laboratory safety and international cooperation, so the world is better prepared for the next pandemic.
