Of Pandemic and the Pathogen

Prof P. Bambroo
It is now more than 4 months since China officially reported the outbreak of COVID – 19 in the country and it continues to surge, running rampant, transcending the global boundaries and conquering the whole world, earning the infamous pandemic status. The pathogen is on the rampage of causing large scale fatalities, ravaging the economies, millions losing their job with each passing day, and threatening new world order too. The virus, that initially looked to be the pathogen of high end hosts, not sparing even the heads of some nations, has since permeated to all sections of the societies, claiming now the lives of underprivileged with greater ease.
Notwithstanding the fact that viruses in general have the tendency to undergo mutations, producing variants and different serotypes that have changed tendency for host preference and the degree of virulence, the origin of the novel human coronavirus SARS – CoV – 2 is still unknown. Many point fingers at Wuhan Institute of Virology for its origin. Luc Montagnier, who reported HIV in 1983 as the causative agent of AIDS, has come out openly in support of ‘Lab Origin’ of this virus. The zoonotic nature of this virus is yet to be established. Together with Severe Acute Respiratory Syndrome (SARS) coronavirus, and Middle East Respiratory Syndrome (MERS) coronavirus, this is the third highly pathogenic human coronavirus that has emerged in the last 2 decades. SARS – CoV – 2 is one of the 37 coronaviruses in the family coronaviridae, the members of which are known to cause respiratory or intestinal infections in humans and other animals.
COVID 19 – A medical tragedy
In the absence of any safe and reliable therapeutic drug against the novel human coronavirus, the disease is spreading at will. The medical world and the researchers are grappling with this challenge. According to WHO, administration of plasma containing antibodies of a treated person, to offer artificial passive immunity among patient of COVID-19, does not enjoy any research based support to the effect of its usefulness.
Vaccine would be the ultimate weapon against this virus and the easy route to resumption of normal work. While Anthony S. Fauci, infectious diseases expert on President Trump’s administration, is presenting a rosy forecast of vaccine against SARS – CoV – 2, the unpalatable truth is that it may not arrive so soon. Till date, there is no report of vaccine development in 18 months. Previous record of developing any entirely new vaccine is at least 4 years. Researchers believe that earliest timeline for the availability of the vaccine against novel human coronavirus, even after fast tracking each stage of its development, may not be before August 2021.
The development process of a new vaccine passes through exploratory stage during which lab research is involved, pre-clinical stage for tissue culture testing or animal testing, clinical stage testing for studies with human subjects and finally its approval and licensure stage. According to latest report of WHO, 8 candidate vaccines from USA, UK, and China are in clinical evaluation stage and 100 candidate vaccines, from different countries, are in pre-clinical evaluation stage. In India, Bharat Biotech Ltd and ICMR, Indian Immunologicals Ltd, Serum Institute of India, Biological E Ltd, Zydus Cadila Ltd and IISc – Mynvax are actively engaged in the development of vaccine against this pathogen, and are in the pre-clinical evaluation stage.
Many viruses undergo antigenic variation and the new variant displaces completely the pre-existing strain. Thus by the time a vaccine is produced, the possibility of emergence of its variants is always there. There are many viruses like HIV, Dengue virus, Chikanguniya etc against which vaccine development venture has not succeeded even after decades of research.
Scientists believe that SARS-CoV-2 does not appear to mutate significantly. This opens the window of hope for a breakthrough in the development of vaccine for this virus. However, any delay in its development will be difficult to bear.
Till a vaccine against this pathogen is available in the market, the COVID – 19 shall continue to be a medical tragedy.
Transmission complexities
The fight against novel human coronavirus poses many challenges due to the complexities of its transmission. The virus appears to be environmentally stable, given its persistence to stay infectious on inanimate surfaces from 2 hrs to few days, in the waste water and water up to 3 days, and its resistance to high atmospheric temperature and high humidity.
Being novel virus the sources of its infection, other than emanating from respiratory secretions, are being unraveled. The entry of this virus into the host cell is facilitated by the key receptor Angiotensin Converting Enzyme 2 (ACE 2) that is found present on the epithelial cells of respiratory system, and intestine.
To establish fecal-oral route of transmission of this virus, scientists in Netherlands generated human small intestinal organoids derived from primary gut epithelial stem cells. Observations of the scientists from Hubrecht Institute, Erasmus University Medical Center, and Maastricht University contained in May 1, 2020 issue of journal Science reveal that these tissue culture cells were readily infected by SARS-CoV and SARS-CoV-2 and the rates of infection were similar across the organoid models, indicating that even low quantities of ACE2 may be enough for the virus to infect epithelial cells of intestine This bolsters a case for intestinal transmission.
The detection of this virus in wastewater at many places could be due to the presence of the virus in human stool, and its nature of environmental stability. This means that water and wastewater aerosols could also be a potential source of SARS-CoV-2 transmission. More extensive testing using not only nose and throat swabs, but also rectal swabs or stool samples may thus be needed. In Indian context, this area assumes great significance in our resolve to control the epidemic.
Besides, the reports of the transmission of the virus from humans to animals, like tigers at Bronx Zoo in USA, house cats in China and Belgium, have added new dimension to the complexity of this pandemic. There could be many such cases of animal infection in India too.
Top it all, the transmission by greater proportion of asymptomatic carrier persons is a huge challenge to deal with. This is why the fight against the COVID-19 appears to be long drawn affair.
Technological breakthrough
There is good news indeed. The country has made an early breakthrough in R&D sector. National Institute of Virology Pune has developed first indigenous antibody detection kit for COVID-19, exhibiting the scientific and technological prowess. This will play a critical role in surveillance of infection. Each kit can test 90 samples in a single run of 2.5 hrs. India is now on a firm footing to take on the virus and prevent its transmission.
Lockdown
The graded approach adopted by India to deal with the COVID – 19 and responding to each situation after thorough evaluation, with proactive decision of lockdown very early in our resolve to save lives and also arrange for livelihood of the needy, and suitably supported by all citizens, has been appreciated world over. The strategy appears to have served the intended purpose of restricting the infection to linear growth, besides providing opportunity to plan and strengthen the health care infrastructure for any large scale eventuality. The nation has drawn up the exigency plan and appears to be now fully equipped to deal with any exponential spike.
Learning to live with the virus
The exit from lockdown assumes great significance. Our nation can ill afford an indefinite lockdown in present form. This has hit the economy in more ways than the obvious. People have become jobless and sufferings of poor have multiplied in the absence of any prospect for earning their livelihood. Staggered exit is a step in right earnest. The MSME is a vulnerable sector in any such unfavorable situation. The announcement of financial stimulus by the Finance Minister will revitalize this sector.
The principle of ‘learning to live with the virus while earning the livelihood’ needs to be adopted. This has to be the premise of revival of economic activity. Face masks and hand sanitizers should be made freely available in the market on subsidized rates. Their free distribution among the slum dwellers, construction workers, and underprivileged sections would discourage the spread of this virus. In any case practice of social distancing and our activities at places of work have to go hand in hand.
We, as responsible citizens, need to rise to the occasion and show respect and follow the measures announced by the National Disaster Management Authority of India with full sincerity and seriousness. It is time that we stand united and cooperate with the healthcare workers to clear the clouds of coronavirus, usher in era of normal activity and contribute to reboot economic growth.
Together, yes we can.
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