2. SARS-COV2
VIRAL CLASSIFICATION A/C to ICTV :-
•
A novel transmissible coronavirus, SARS coronavirus 2 (SARS-CoV-2), was
noted to cause an influenza-like disease ranging from mild respiratory
symptoms to severe lung injury, multi-organ failure, and death.
NOTE : SARS-COV2, first case was reported in Wuhan(CHINA) in 2019 and said to have
zoonotic transmission (like its sister viruses SARS and MERS) from bats to pangolin to
humans. However, in a recent research it was seen the SARS COV 2 is an airborne pathogen,
thus it can spread from human to human more rapidly.
REALM RIBOVIRIA
KINGDOM ORTHORNAVIRAE
PHYLUM PISUVIRICOTA
CLASS PISONIVIRICETES
ORDER NIDOVIRALES
FAMILY CORONAVIRIDAE
GENUS BETACORONAVIRUS
STRAIN SEVERE ACUTE RESPIRATORY
SYNDROME CORONAVIRUS 2
3.
4.
5.
6. NOTE: Spike glycoprotein in SARS-COV2 is made up of two subunits- SUBUNIT 1 &
SUBUNIT 2.
Subunit 1 - it is 70% similar to other COVs but the core receptor binding region is highly
conserved .These amino acid differences are responsible for direct interaction between
host receptors and spike protein.
Subunit 2 - it is highly conserved and shares 99% identity with two bats SARS like COVs.
10. A/C to a randomized controlled clinical trial called RECOVERY conducted in the United Kingdom ,
a steroid drug called dexamethasone, is the first shown to reduce deaths from the coronavirus.
Dexamethasone, in contrast, is a medical staple found on pharmacy shelves worldwide and is
available as a pill — a particular benefit as coronavirus infections continue to rise in countries with
limited access to health care.
Treatment guidelines from the World Health Organization and many countries have cautioned
against treating people with coronavirus with steroids, and some investigators were
concerned about anecdotal reports of widespread steroid treatment.
Data from steroid trials during outbreaks of severe acute respiratory syndrome and Middle
East respiratory syndrome caused by related coronaviruses were inconclusive, he says.
Nevertheless, given dexamethasone’s broad availability, and some promising results from
steroid studies in previous outbreaks, RECOVERY investigators considered it important to
test the treatment in a rigorous trial.
The dexamethasone arm enrolled 2,100 participants who received the drug at a low-to-
moderate dose of 6 milligrams per day for 10 days, and compared how they fared against
about 4,300 people who received standard care for COVID-19.
Dexamethasone’s effect was most striking among patients on ventilators. Those who were
receiving oxygen therapy but were not on ventilators also saw improvement: their risk of dying
was reduced by 20%. The steroid had no effect on people with less severe cases of COVID-
19 — those not receiving oxygen or ventilation.
The RECOVERY trial indicates that at the doses tested, the benefits of steroid treatment can
outweigh the potential harm and can be given to pretty much anyone.
11. PROPOSED MECHANISM OF ACTION
ON COVID PATIENTS
The severe patients with COVID-19 suffer a hyper inflammatory state—a
cytokine storm—that has features in common with a rare haematological
condition called haemophagocytic lymphohistiocytosis. Immune suppression
should help such patients.By contrast, immune suppression during the early
phase of the viral infection might allow increased viral replication and aggravate
the disease.
DEXAMETHASONE
13. Itolizumab is the first novel biologic therapy to be approved treating patients with
moderate to severe COVID-19 complications.
The approval of Itolizumab, from the DCGI is based on the results from the
successful conclusion of a randomized, controlled clinical trial at multiple hospitals in
Mumbai and New Delhi. The study focused on the safety and efficacy of Itolizumab
in preventing cytokine release syndrome (CRS) in moderate to severe ARDS (acute
respiratory distress syndrome) patients due to COVID-19.
Patients who were with initial oxygen saturation of less than 80% and would have
been put on ventilator support with little chance of survival, recovered completely
when treated with Itolizumab and got discharged.
Injection 25mg/5mL solution for emergency use in India for the treatment of cytokine
release syndrome (CRS) in moderate to severe ARDS (acute respiratory distress
syndrome) patients due to COVID-19.
The SARS-CoV-2 virus has been observed to induce an overreaction of the immune
system, generating a large number of cytokines that can cause severe damage to the
lungs and other organs .
Itolizumab’s unique mechanism of action of immunomodulation involves binding to
the CD6 receptor and blocking the activation of T lymphocytes, which in turn
suppresses the pro-inflammatory cytokines, thus reducing the cytokine storm and
deadly inflammatory response.
19. RUSSIAN VACCINE
Russia has become the 1st nation to complete clinical trials of
COVID-19 vaccine on humans, and the results have proven
the medication's effectiveness.
Russia had allowed clinical trials of two forms of a potential
coronavirus vaccine developed by the Gamaleya National Research Center for
Epidemiology and Microbiology on June 18.
The 1st vaccine, in the form of a solution for intramuscular administration, was
carried out at the Burdenko Military Hospital.
Another vaccine, in the form of a powder for the preparation of a solution for
intramuscular administration, was carried out at Sechenov First Moscow State
Medical University.
The 1st stage of research on the vaccine at Sechenov University involved a group of
18 volunteers and the second group involved 20 volunteers. After vaccination, all
volunteers were expected to remain in isolation in a hospital for 28 days.
proves that volunteers of the 1st and second groups are forming an immune response
after injections of the vaccine against the coronavirus,“ according to an earlier
statement from the Russian Defense Ministry.
35. CORRECTLY FITTED MASK=REDUCE
TRANSMISSION ?
A large proportion of the spread of coronavirus disease 2019 (COVID-19) appears
to be occurring through airborne transmission of aerosols produced by
asymptomatic individuals during breathing and speaking.
Aerosols can accumulate, remain infectious in indoor air for hours, and be easily
inhaled deep into the lungs.
There are two major respiratory virus transmission pathways: contact (direct or
indirect between people and with contaminated surfaces) and airborne inhalation.
Respiratory droplet size has been shown to affect the severity of disease. In the case
of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), it is possible
that submicron virus-containing aerosols are being transferred deep into the
alveolar region of the lungs, where immune responses seem to be temporarily
bypassed.
SARSCoV-2 has been shown to replicate three times faster than SARS-CoV-1 and
thus can rapidly spread to the pharynx, from which it can be shed before the innate
immune response becomes activated and produces symptoms (6). By the time
symptoms occur, the patient has transmitted the virus without knowing.
In Wuhan, China, it has been estimated that undiagnosed cases of COVID-19
infection, who were presumably asymptomatic, were responsible for up to 79% of
viral infections
36. OUTDOOR ENVIRONMENT
numerous factors will determine the concentrations
and distance traveled, and whether respiratory
viruses remain infectious in aerosols.
winds often occur and can transport infectious
droplets and aerosols long distances. Asymptomatic
individuals who are speaking while exercising can
release infectious aerosols that can be picked up by
airstreams
Viral concentrations will be more rapidly diluted
outdoors.
Viruses can attach to other particles such as dust and
pollution, which can modify the aerodynamic
characteristics and increase dispersion.
Moreover, people living in areas with higher
concentrations of air pollution have been shown to
have higher severity of COVID-19.
Because respiratory viruses can remain airborne for
prolonged periods before being inhaled by a
potential host, studies are needed to characterize the
factors leading to loss of infectivity over time in a
variety of outdoor environments over a range of
conditions
37. INDOOR ENVIRONMENT
In an enclosed room with asymptomatic individuals, infectious aerosol concentrations can
increase over time. Overall, the probability of becoming infected indoors will depend on the
total amount of SARS-CoV-2 inhaled.
Ultimately, the amount of ventilation, number of people, how long one visits an indoor facility,
and activities that affect airflow will all modulate viral transmission pathways and exposure.
MASK
Masks provide a critical barrier, reducing the number of infectious viruses in exhaled breath,
especially of asymptomatic people and those with mild symptoms.
Surgical mask material reduces the likelihood and severity of COVID-19 by substantially
reducing airborne viral concentrations.
Masks can also protect uninfected individuals from SARS CoV- 2 aerosols and droplets.
The aerosol filtering efficiency of different materials, thicknesses, and layers used in properly
fitted homemade masks was recently found to be similar to that of the medical masks that
were tested . Thus, the option of universal masking is no longer held back by shortages.
39. SOME IDEAS UNDER DEVELOPMENT :-
• a face mask with embedded biosensors that can detect the presence of virus on the
wearer’s breath
• Other devices under exploration use electronic or optical readouts to detect viruses
within minutes from any type of sample, and yet others engineer sophisticated micro
and Nano fluidic systems onto low-cost substrates, such as silicon or even paper . The
idea is to bring laboratory-like precision to use at the bedside, at home or in low-
resource settings.
40.
41. REFERENCES
• Ledford. Heidi; STEROID IS FIRST DRUG SHOWN TO PREVENT
DEATHS FROM COVID-19; Nature, Vol 582, 25 June 2020
• Press Release; Biocon’s Breakthrough Drug Itolizumab Receives DCGI Nod
for its Use in Moderate to Severe COVID-19 Patients; Drug to Save Many
Lives; Bengaluru, Karnataka, India – July 11, 2020
• Russia first nation to finish human trials for Covid vaccine; The Economic Times,
E-paper, English edition, 13th July 2020
• Open letter; Single cell transcriptome revealed SARS-CoV-2 entry genes enriched
in colon tissues and associated with coronavirus infection and cytokine
production; Signal Transduction and Targeted Therapy; Nature; (2020), 5;121
• Kimberly A. Prather, Chia C. Wang and Robert T. Schooley; Reducing
transmission of SARS-CoV-2; Science mag; 368 (6498), 1422-1424.
• News Letter WHO; 2020