MIC 201 test 1 lecture 11 (9/28) Flashcards

diff btw covid and AIDS

• covid is acute (get once and done after)
  • resolves itself
• HIV is chronic infection
  • has acute phase, but never clear the pathogen

• think real # covid deaths much higher
• think not accurately reported in many countries
  • excess deaths = more than should be occurring
  • when studied # excess deaths in diff countries, found that excess deaths are due to covid - much higher than reported COVID deaths
  • india in beginning did not have many excess deaths - were not reporting them
  • in US, believe real # deaths is 1.37 x higher than reported
• estimated actuslly 18 million deaths due to COVID, but global total reported was ONLY 6 million

• life expectancy dropped almost 3 yrs
• indicator of impact epidemic had on country

disease itself

• viral part of infection
• disease part is after
  • disease of immune response
    • bc WHERE immune response occuring - if infection get deep into lungs, have immune response in delicate tissue in lungs (only 2 cell layers in lungs, so is vulnurable)
    • = compromised lung function = most common cause of COVID mortality

mild disease is primarily limited to infection of upper airways

if infection extends to lower airways, immune responses occurring in air sacs reduce gas exchange

stronger immune responses are associated with worse disease prognosis

still mysterious: long COVID nervous system complications and COVID in children

• since so many ppl in world have been infected, it makes sense that ppl will have diff/weird responses
• kids - usually fine (generally develop less severe disease than older adults) - unusual for respiratory disease
• long covid - lot of research bc dont fully understand
  • not clear why some ppl have symptoms that persist

• lab made - NO
• lab escape - possible, but unliekly
  • does NOT mean made in lab, but could have been HANDLED in lab where escaped
  • means its a natural virus, just studied in a lab but escaped
  • cant rule this out
• consensus - SARS derived from some combinations of wild and semi-domesticated animals

bats are reservoir of viruses

• dont know why
• sars-like viruses naturally infect them
• maybe came from wet market

...

genetic material - RNA

enveloped - phospholipid membrane

sars, flue, HIV all enveloped

...

1. covid genetic material does NOT go to the nucleus
   • when cell infected with HIV, genetic material inegrate into chromosome - makes HIV so complicated (retrovirus)
   • sars go thru replication cycle (without involving nucleus/genetics)
     • genetic material stays away from nucleus

remdezivir - interfere w/ genetic replication (targets viral replication)

less than HIV (by a lot)

• HIV is highly mutagenic
• SARS has mutation rate - but not nearly as much as HIV
  • few virions of SARS, even though SO MANY people get it, so considering amount of pple who have gotten it, mutation rate not very high
  • while HIV mutates on individual level (even in individual)
• mutations occur in spike proteinsfor SARS (S protein)
  • affect how spike protein interact w/ receptor or mutations impact how antibodies interact w/ them
  • bind ACE2 receptor
  • ones worry abt:
    • ones that bind ACE2 (BETTER)
    • ones bind neutralizing antibodies (WORSE BC LOWER IMMUNE SRENGTH AGAINST IT)
• mutation rate of sars is at LEAST 100x lower than HIV (likely even less)

• HIV, immune system cannot make antibodies to neutralize it bc is good at keeping self from being targeted by immune system = why we dont have vaccine
• good neutralizing antibodies - interfere w/ spike proteins + ACE2 receptor
  • prevent it from interacting with ACE2 (physically interferes + prevents infection)

all about making antibodies vs spike protein

spike protein = distinguishing feature of SARS

• naturally
• vaccination
• surviving infection
• artificially (passive immunization)
• monoclonal antibody treatment - inject w/ antibodies

• no vaccine for HIV
• vaccine for COVID in 10 months

• covid is curable
• HIV is NOT currently curable

biggest difference btw covid and HIV