Review: The Baltimore Scheme of Viruses PDF

D ' skp,bi bleofbloloyyCalreadymentioel Review: The Baltimore scheme of viruses By 1975 Nobel laureate (for their discoveries concerning the interaction between tumor viruses and the genetic material of the cell), virologist, David Baltimore. Based on the genetic materials...

D ' skp,bi bleofbloloyyCalreadymentioel Review: The Baltimore scheme of viruses By 1975 Nobel laureate (for their discoveries concerning the interaction between tumor viruses and the genetic material of the cell), virologist, David Baltimore. Based on the genetic materials of the viruses. Coronaviruses Figure 10.2 Virus entry: Spike protein and ACE2 receptor Spike (S) protein: a glycoprotein spike on the viral surface. ACE2 (Angiotensin converting enzyme 2): the major SARS receptor protein on the host cell which binds to the spike protein; S protein only binds to the ACE2 genes in specific host species. TMPRSS2 (Transmembrane serine protease 2): a protease facilitates viral particle entry into host cells. https://www.biomol.com/resources/biomol-blog/ace2-the-sars-cov-2-receptor  Infection cycle of the virus Only RNA-dependent RNA polymerase (RdRp, encoded by nsp12) is translated from the (+) genomic RNA directly. Genomic RNA used as template to produce (–) strands (multiple lengths) from which (+) mRNAs are produced (by RdRp) and translated. Virions assembled in Golgi complex and released membrane from cell surface ^ 」 as an enveloped virus.  Disease characteristics Covid-19 is highly infectious with z R0 at ~2.5. Omicron BA.5 r0 = 18.6 R0 (pronounced “R naught”): the ^ reproduction number: – If R0 is less than 1, each existing infection causes less than one new infection. In this case, the disease will decline and eventually die out. – If R0 equals 1, each existing infection causes one new infection. The disease will stay alive and stable, but there won’t be an outbreak or an epidemic. – If R0 is more than 1, each existing infection causes more than one new infection. The disease will be transmitted between people, and there may be an outbreak or epidemic. https://www.thelancet.com/pdfs/journals/laninf/PIIS1473-3099(20)30484-9.pdf  Symptoms include fever, cough, fatigue, shortness of breath, and loss of smell and taste. Can develop into severe respiratory syndromes. Asymptomatic carrier is prevalent. Death is predominately in aged population. sAs to weak gesk biaped old ,.  Disease management Mask, good hygiene practice, and Oxygen therapy, ventilator and ECMO social distancing (artificial lung ) for critical care stjude.org (iStock/Getty Images) Temporary hospitals to cope with Community center to isolate patients the burst of needs for hospital beds without or with mild symptoms. http://tbs.seoul.kr/eFm/newsView.do?typ_800=M&idx_800=2385748&seq_800=  Transmission routes 1. Direct contact with contaminated surfaces. 2. Aerosols produced by breathing, coughing, sneezing. 3. Cold surfaces/environment or cold chain transportation: viruses have been detected on the surfaces of frozen food and packaging and research showed that viruses can be alive for weeks on cold surfaces. Wuhan Seafood market - ? Beijing Xin Fa Di market ( ) – cold working environment or imported food (?) Dalian seafood company – imported seafood Positive detection in shrimps imported from South America https://news.cgtn.com/ Covid-19 aerosol review: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7293495/  Human-animal transmission Covid-19 is a zoonotic disease. SARS-CoV-2 can infection cats (domestic cat, tiger, lion), dog, civet, bat, ferret, monkey, mink etc.; But not, pig, chicken, mice and rat. So far, evidences showed that pet owner can pass the virus to the pet but not the other way. A dog infected in HK Ferret ( skip) Vaccine development Various types of vaccine are being tested. Most vaccine candidates are targeting the S protein. India Around 10 vaccine candidates China are in Phase III clinical trial. Key parameters: Safety Russia Efficacy - at least 50% required by US FDA Cost Availabilities – production, transportation, access Acceptance by the public US, EU