The double mutuated Corona Virus
Conducting a study related to Virus, its clear that Virus mutuates all the time. Some of these mutuations may weaken the virus and while the other strengthens them. Virus is spreading all around the world faster than other pre existing variants. Scientists are trying to continously monitor and respond to this pandemic but the vaccines are only effective to a particular limit.
While looking at the source from which all the spreading started, yes no doubt its "China", It was for a butler in Wuhan meat market primarily corona was infected and this is the idea the virus might have originated from elsewhere via the farming, catching, processing, transporting, refrigeration or freezing of food. Was that food ice cream, fish, wildlife meat? We don’t know. It’s unproven that this triggered the origin of the virus itself. But to what extent did it contribute to its spread? Again, we don’t know.The emergence of SARS-CoV-2 was first observed when cases of unexplained pneumonia were noted
in the city of Wuhan, China. (1) During the first weeks of the epidemic in Wuhan, an association was
noted between the early cases and the Wuhan Huanan Seafood Wholesale Market (hereafter referred to
as the “Huanan market”); cases were mainly reported in operating dealers and vendors.(1) The
authorities closed the market on 1 January 2020 for environmental sanitation and disinfection. The
market, which predominantly sold aquatic products and seafood as well as some farmed wild animal
products, was initially suspected to be the epicentre of the epidemic, suggesting an event at the humananimal interface. Retrospective investigations identified additional cases with onset of disease in
December 2019, and not all the early cases reported an association with the Huanan Market.(2)
Although the role of civets as intermediate hosts in the outbreak of severe acute respiratory syndrome
(SARS) in 2002-2004 had been favoured and a role for pangolins in the outbreak of COVID-19 was
initially posited, subsequent epidemiological and epizootic studies have not substantiated the
contribution of these animals in transmission to humans. The possible intermediate host of SARS-CoV2 remains elusive.
Bats have been identified as the hosts of a series of important zoonotic viruses (for example, Nipah
virus, Hendra virus and SARS-CoV), including coronaviruses with considerable genetic diversity.(3, 4)
Of particular relevance with regard to COVID-19 are those coronaviruses that were found to be
associated with the outbreaks in humans of SARS in 2002 and the Middle East respiratory syndrome
(MERS) in 2013.(5)
The causative virus of COVID-19 was rapidly isolated from patients and sequenced, with the results
from China subsequently being shared and published in January 2020.(6) The findings showed that it
was a positive-stranded RNA virus belonging to the Coronaviridae family (a subgroup B
betacoronavirus) and was new to humans. In the early work, analysis of the genomic sequence of the
new virus (SARS-CoV-2) showed high homology with that of the coronavirus that caused SARS in
2002-2004, namely SARS-CoV (another subgroup B betacoronavirus).(5) Over the next year extensive
work globally on sequences and phylogeny followed and the results have been shared internationally
and stored through the GISAID platform
SARS-CoV-2 also shares a 96.2% homology with a sequence of a strain of coronavirus (RaTG13)
previously identified by genetic sequencing from a horseshoe bat sample (Rhinolophus species) and to
a lesser extent with a strain isolated from pangolins. The RaTG13 virus sequence is the closest known
sequence to SARS-CoV-2.
As with the coronaviruses that cause SARS and MERS, human-to-human transmission of SARS-CoV2 was soon established, (7) but the virus demonstrated much greater infectivity than these other two
coronaviruses. (8) SARS-CoV-2 shows a broad tissue tropism, in particular binding through its spike
protein to angiotensin-converting enzyme 2 (ACE2). It also directly infects endothelial cells lining the
blood vessels, unusually for a human respiratory virus. Other novel pathological features of the virus
are hypercoagulability and the excessive multi-organ immune system response and long-term sequelae.
People infected with SARS-CoV-2 appear to be most infectious at the time of onset of symptoms but
were also infectious in the days before onset. Infections can be asymptomatic, cause a mild illness or
result in severe disease and death.
In February 2020 the joint WHO-China mission on COVID-19 (9) was convened to inform planning in
China and internationally on the next steps in the response to the ongoing outbreak of COVID-19. Its
major objectives were:
• to enhance understanding of the evolving COVID-19 outbreak in China and the nature and
impact of ongoing containment measures;
• to share knowledge on the COVID-19 response and preparedness measures being implemented
in countries affected by or at risk of importations of COVID-19;
• to generate recommendations for adjusting COVID-19 containment and response measures in
China and internationally; and
• to establish priorities for a collaborative programme of work, research and development to
address critical gaps in knowledge and response and readiness tools and activities.
In May 2020, the Seventy-third World Health Assembly adopted resolution WHA73.1 on the COVID19 response. Through the resolution, Members States requested the Director-General “to continue to
work closely with the World Organisation for Animal Health (OIE), the Food and Agriculture
Organization of the United Nations (FAO) and countries, as part of the One-Health Approach to identify
the zoonotic source of the virus and the route of introduction to the human population, including the
possible role of intermediate hosts, including through efforts such as scientific and collaborative field
missions, which will enable targeted interventions and a research agenda to reduce the risk of similar
events occurring, as well as to provide guidance on how to prevent infection with severe acute
respiratory syndrome coronavirus 2 (SARS-CoV-2) in animals and humans and prevent the
establishment of new zoonotic reservoirs, as well as to reduce further risks of emergence and
transmission of zoonotic diseases”.
In July 2020, building on the recommendations of the Seventy-third World Health Assembly, the WHO
sent an advance team to China to agree on a way forward to better understand the origins of the virus.
The agreed Terms of Reference (10) defined the scope of studies, the main guiding principles and the
main expected deliverables. These ToRs envisaged two phases of studies: short-term studies (Phase 1)
to better understand how the virus started to circulate in Wuhan; and, building on the findings and the
published scientific literature, longer-term studies (Phase 2). The ToRs included the setting up of a joint
international team of experts that would help analyse Phase 1 studies outcomes and design, and support
and conduct the Phase 2 studies. The work aimed to contribute to improving the understanding of the
virus origins. The overall results and findings would benefit improved global preparedness and response
to SARS-CoV-2 and emerging zoonotic diseases of similar origin.
Before the joint study, the earliest recognized cases of COVID-19 in Wuhan were thought to have
occurred in early December 2019.(1) Preliminary information from surveillance of severe pneumonia
had suggested no unusual clustering or departure from trends in the weeks and months preceding these
first reported cases. As SARS-CoV-2 infection may, however, be asymptomatic or cause only mild
illness in many individuals,(2-4) it is likely that others were infected at the time of the recognition of
the early cases and that transmission could have been occurring in the community before this point.
Investigation into the possible occurrence of earlier cases is therefore important.
Many of the early cases were reported to have a link to the Huanan market, a place where animals and
animal products were sold to the public. Some reports have suggested the zoonotic spread of SARSCoV-2 through this market, although the role of the market, as either the source of the initial
transmission of the virus to humans or as an amplifier of the early epidemic, was unclear, as several
early cases reported no link to the Huanan market or any other market in Wuhan.(5)
Several Phase 1 studies were agreed following the drafting of the ToRs in July 20202
, and work was
carried out ahead of the arrival of the international team in January 2021. This work included extensive
data collection, data cleaning, review of clinical records, patient interviews and testing, and preparatory
analyses. The studies were reviewed in depth by the joint international WHO/Chinese team, and
additional analyses were done based on these reviews. The overall focus of the studies was to determine:
(1) whether there was evidence of transmission of SARS-CoV-2 in Wuhan or Hubei Province in
the period preceding the recognized outbreak in Wuhan in December 2019 using routine disease
and death surveillance data, review of clinical records and targeted SARS-CoV-2 laboratory
testing;
(2) whether there was evidence of transmission of SARS-CoV-2 in the wider population of Wuhan
or Hubei Province at the time the outbreak was recognized in Wuhan in December 2019 using
information from the cases reported with onset in that month; and
(3) whether the epidemiological characteristics of the early cases associated with the Huanan
market pointed to a specific time, location or source of the introduction of infection into the
market at the beginning of the outbreak.
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