Sep 19 (IANS) In the last 24 hours, India logged 4,858 new Covid-19 cases and 18 deaths, the Union Health Ministry said on Monday.
The new fatalities have pushed the nationwide death toll to 5,28,355.
The active caseload rose to 48,027, accounting for 0.11 per cent of the country’s total positive cases.
The recovery of 4,735 patients in the last 24 hours took the cumulative tally to 4,39,62,664. Consequently, India’s recovery rate stands at 98.71 per cent.
Meanwhile, the daily and weekly positivity rates stood at 2.76 per cent and 1.78 per cent, respectively.
Covid cases/Ians
Also in the same period, a total of 1,75,935 tests were conducted across the country, increasing the overall tally to over 89.17 crore.
As of Monday morning, India’s Covid-19 vaccination coverage exceeded 216.70 crore.
Over 4.08 crore adolescents have been administered with a first dose of Covid-19 jab since the beginning of vaccination drive for this age bracket.
The Union Government is committed to accelerating the pace and expanding the scope of COVID-19 vaccination throughout the country. The nationwide COVID 19 vaccination started on 16th January 2021. The new phase of universalization of COVID-19 vaccination commenced from 21st June 2021. The vaccination drive has been ramped up through availability of more vaccines, advance visibility of vaccine availability to States and UTs for enabling better planning by them, and streamlining the vaccine supply chain.
As part of the nationwide vaccination drive, Government of India has been supporting the States and UTs by providing them COVID Vaccines free of cost. In the new phase of the universalization of the COVID19 vaccination drive, the Union Government will procure and supply (free of cost) 75% of the vaccines being produced by the vaccine manufacturers in the country to States and UTs.
covid vaccines doses
More than 201.88 crore (2,01,88,89,325) vaccine doses have been provided to States/UTs so far through Govt. of India (free of cost channel) and through direct state procurement category.
More than5.58Cr (5,58,87,590) balance and unutilized COVID Vaccine doses are still available with the States/UTs to be administered.
Scientists from Hokkaido University in Japan have discovered a novel defensive response to SARS-CoV-2 or Covid-19 that involves the viral pattern recognition receptor RIG-I. Upregulating expression of this protein could strengthen the immune response in COPD patients.
In the 18 months since the first report of COVID-19 and the spread of the pandemic, there has been a large amount of research into understanding it and developing menas to treat it. COVID-19 does not affect all infected individuals equally. Many individuals are asymptomatic; of those who are symptomatic, the large majority have mild symptoms, and only a small number have severe cases. The reasons for this are not fully understood and are an important area of ongoing research.
The team of scientists from Hokkaido University, led by Professor Akinori Takaoka of the Institute for Genetic Medicine, has shown that RIG-I, a biological molecule that detects RNA viruses, restrains SARS-CoV-2 replication in human lung cells. Their findings, which could help predict COVID-19 patient outcomes, were published in the journal Nature Immunology.
Covid pandemic
To date, over 162 million people have been affected by COVID-19. About 40% – 45% of these individuals are asymptomatic; as for the rest, around 35% – 40% experienced a mild form of the disease, while the remaining 19% were affected by symptoms that were severe enough to warrant hospitalisation or were fatal, which are usually associated with comorbidities and risk factors such as chronic obstructive pulmonary disease (COPD). This range of symptoms indicates that there are vast differences between individual responses to the virus.
SARS-CoV-2 replication is suppressed by RIG-I. When pulmonary cells that do not express RIG-I (left) are exposed to SARS-CoV-2, viral spike proteins (green) are detected as soon as 5 days (72 hours) after exposure. In normal cells (right), SARS-CoV-2 replication is suppressed / Taisho Yamada, et al. Nature Immunology. May 11, 2021
Microbial pathogens in our body are detected by proteins called pattern recognition receptors (PRRs), which also trigger immune responses to these pathogens. Viral infections are detected by a subset of PRRs; the scientists focused their attention on the protein RIG-I, which belongs to this subset. RIG-I is known to be critical for the detection and response to RNA viruses such as the influenza virus.
In experiments carried out in cell culture lines, the scientists found that there was little innate immune response to SARS-CoV-2 in pulmonary cells, suggesting the signaling pathway leading to immune response was aborted. Nevertheless, viral replication was suppressed. The scientists investigated the role of RIG-I and found that its deficiency caused increased viral replication. Further experiments confirmed that the suppression of viral replication was dependent on RIG-I.
A single previous study has shown that RIG-I expression is downregulated in pulmonary cells of COPD patients. Using primary pulmonary cells from two COPD patients, the scientists showed that this downregulation of RIG-I resulted in the detection of viral replication after 5 days .
Taisho Yamada (left), first author, and Akinori Takaoka (right), communicating author of the paper / Photo: Taisho Yamada, Akinori Takaoka
They also demonstrated that treatment of these COPD cells with all-trans retinoic acid (ATRA), which upregulates the expression of RIG-I, significantly reduced viral titres in the cells. Furthermore, using RIG-I mutants, they were able to elucidate the mechanisms by which RIG-I suppressed SARS-CoV-2 replication: The helicase domain, a structural element in RIG-I, interacts with the viral RNA, blocking a virus-derived enzyme responsible for replication.
This study has demonstrated a unique viral recognition mode of RIG-I, termed the RIG-I-mediated signaling-abortive anti-SARS-CoV-2 defense mechanism. It has also indicated that RIG-I expression levels are one of the potential parameters for the prediction of COVID-19 patient outcomes. Further work must be done to uncover factors or conditions that modulate RIG-I expression levels, and may lead to new strategies to control SARS-CoV-2 infection.
