China
Africa
Explore chapters and articles related to this topic
Bioprocessing of viral vaccines––Introduction
Published in Amine Kamen, Laura Cervera, Bioprocessing of Viral Vaccines, 2023
The current COVID-19 pandemic has put the focus on the development process of vaccines and their safety and efficacy. However, this is not the first pandemic that has occurred. By the end of World War I, in 1918, the Spanish Flu (which was an H1N1 influenza-type virus) caused between 30 and 100 million deaths. SARS (Severe Acute Respiratory Syndrome), with a mortality of 10%, appeared in China in 2002. The H1N1 pandemic (2009), called the swine flu, showed that viruses can transmit via animals. All these viruses are RNA viruses, meaning that evolution is possible. MERS, Middle East Respiratory Syndrome, with a mortality of 30%, appeared in Saudi Arabia in 2012. MERS has been thereafter associated with close contact of humans with dromedary camels as the vehicle of disease transmission and has spread to other countries [22].
Selenium-biofortified herbs as antivirals?
Published in Gary Bañuelos, Zhi-Qing Lin, Dongli Liang, Xue-bin Yin, Selenium Research for Environment and Human Health: Perspectives, Technologies and Advancements, 2019
Viruses comprising RNA cause a range of conditions in humans, from relatively mild (e.g. rhinoviruses causing the common cold) to very severe (e.g. Ebola, with a case fatality of around 60%). Influenza, polio, measles, hepatitis A and C and AIDS are all caused by RNA viruses. The Spanish Flu pandemic of 1918–19 and the Black Death of the 14th century in Europe have been the most devastating disease events in history, each causing an estimated 50 million fatalities (Scott & Duncan 2001, Benedictow 2005, Chandra & Kassens-Noor 2014). Some researchers regard the rapid spread and symptoms of the Black Death to be more indicative of an Ebola-type hemorrhagic RNA viral disease than the plague bacillus (Scott & Duncan 2001). In livestock, RNA virus diseases include bird flu, equine flu, swine fever and foot and mouth disease.
Antiviral Drugs as Tools for Nanomedicine
Published in Devarajan Thangadurai, Saher Islam, Charles Oluwaseun Adetunji, Viral and Antiviral Nanomaterials, 2022
Viruses on the basis of the type of their genome are classified into DNA viruses and RNA viruses. In DNA viruses, viral DNA enters into the host cell nucleus, gets transcribed into mRNA using host cell RNA polymerase, and translates into various virus-specific proteins. The proteins so formed contain some enzymes, which aid in synthesising more viral DNA as well as proteins. Once the virion particles are assembled, these are released by budding or after cell lysis. A retrovirus is a type of virus that has RNA genome; it inserts RNA into the DNA of a host cell, leading to genomic alterations. Within the cytoplasm, the virus uses its reverse transcriptase enzyme and produces DNA from its RNA genome; that is why named as retro (backwards). This new DNA gets incorporated into the host genome by an integrase enzyme. The host cell cannot distinguish it and treats the viral DNA as part of its own genome, resulting in transcription and translation of the integrated viral genes along with its own genes, producing the proteins required to assemble new copies of the virus. Two genes, namely viral genes (v-onc) and cellular genes (c-onc), have been identified, wherein c-onc genes regulate cellular growth (by encoding for growth factors, cellular receptors, signalling and regulatory proteins, DNA binding proteins) and differentiation, but like their viral counterparts, these are mutated. In case of HTLVs, these viruses have a transactivating gene (tax gene), which is essential for replication and transactivates several cellular genes leading to transformation. Such multigenic events occurring result in the development of HTLV-induced leukemia.
Graph theoretic approach for calculation of new Banhatti indices VIA recent algebraic polynomials with a chemical application
Published in Molecular Physics, 2023
Esra Öztürk Sözen, Elif Eryaşar
Coronaviruses are a type of RNA viruses. They can mutate over and over than DNA viruses, to keep alive. This case causes getting under control of the disease for a longer time. Even it might cause result in death for patients who are exposed to the virus. It caused many outbreaks such as SARS and MERS in the past too. So, studies are presently targeting SARS-CoV viruses in the literature [1,2]. Because this virus affected only far east countries and continued for a short time, the studies for developing drugs in this area were not continued. But if it were, perhaps the progress of the pandemic would change today. This new type of coronavirus is also known as SARS-CoV-2 in the medical literature today since it has a fairly similar gen permutation with SARS-CoV that has been appeared in Hong Kong in 2003 [3]. As there is no medicine yet for SARS-CoV-2, developing antiviral drugs with a wide spectrum is of vital importance.