SARS-CoV-2 Biology (Lec.13) "Lecture 12" was when class took exam 2.
Friday, October 30, 2020 10:37 PM
• COVID-19 stands for the Corona Virus Disease -2019.
• (+) ssRNA virus. (SARS-CoV-2 genome has been sequenced.)
• SYMPTOMS Respiratory illness causing fever, cough, and shortness of breath-- severe cases
involve pneumonia.
○ About 90% will get pneumonitis (inflammation of lung tissue), caused by infection of lower
respiratory tract.
• Nasal swab tests are made to capture viruses outside of host cells (within the nose).
• 11.5% of people in OC have antibodies, much higher than what was expected. Yet not enough to
account for herd immunity.
• IMPACT on immune system: loss of taste/smell, headaches, fever/coughs/rashes.
• q-PCR: measuring the amt of (viral) RNA within a sample. In SARS-CoV-2 positive pts, COVID-19
q-PCR tests for stool and nasopharyngeal samples have gradually lowering rates over time. (Viral
RNA DECs due to exposure leading to memory B cells that can launch an immune response
quickly when exposed again.)
○ Stool samples have caught COVID patients before they set foot on campus. (Arizona State)
• Virus has been constantly mutating, but still don't know if they're becoming "more contagious," or
have gotten any worse.
○ However, mutations don't always have to be deleterious (harmful).
○ Some regions in the genome are less likely to mutate -> those regions are being targeted for
vaccine candidates.
○ Even though it is constantly mutating, it is not mutating rapidly, as compared to the flu virus--
needs an updated vaccine every year, to keep up with the new strain.
• SARS-CoV-2 has relatively low genetic diversity (less RNA progeny) compared to other viral
pathogens. -> Varying strains should not impede development of vaccine.
• False positive or false negative results to a COVID diagnostic tests?
○ Nasal swab or saliva test by qPCR.
○ Blood test for antibodies.
○ False (-): not enough material collected, sampling/storage problems, lack of test sensitivity
○ False (+): contamination, cross-reactivity picking up false signal (RAs handling sample are
positive), etc.
• Antibody response happens a week after infection, and it's activity is prolonged even after virus
symptoms/infections are gone.
• Long-haulers: ppl who have been showing symptoms for many months-- prolonged symptoms.
SARS-CoV-2 is a (+) ssRNA virus whose viral RNA DECs overtime due to production of
memory B cells (propose an immune response when exposed again). The virus is
constantly mutating, but we don’t know if those mutations are deleterious, nor is it
mutating rapidly. The virus has LOW genetic diversity; dif strains will not impede vaccine
development. False (-) are due to not enough collection, sampling/storage problems, test
lacking sensitivity. False (+) are due to contamination, cross-reactivity picking up a fake
signal.
Friday, October 30, 2020 10:37 PM
• COVID-19 stands for the Corona Virus Disease -2019.
• (+) ssRNA virus. (SARS-CoV-2 genome has been sequenced.)
• SYMPTOMS Respiratory illness causing fever, cough, and shortness of breath-- severe cases
involve pneumonia.
○ About 90% will get pneumonitis (inflammation of lung tissue), caused by infection of lower
respiratory tract.
• Nasal swab tests are made to capture viruses outside of host cells (within the nose).
• 11.5% of people in OC have antibodies, much higher than what was expected. Yet not enough to
account for herd immunity.
• IMPACT on immune system: loss of taste/smell, headaches, fever/coughs/rashes.
• q-PCR: measuring the amt of (viral) RNA within a sample. In SARS-CoV-2 positive pts, COVID-19
q-PCR tests for stool and nasopharyngeal samples have gradually lowering rates over time. (Viral
RNA DECs due to exposure leading to memory B cells that can launch an immune response
quickly when exposed again.)
○ Stool samples have caught COVID patients before they set foot on campus. (Arizona State)
• Virus has been constantly mutating, but still don't know if they're becoming "more contagious," or
have gotten any worse.
○ However, mutations don't always have to be deleterious (harmful).
○ Some regions in the genome are less likely to mutate -> those regions are being targeted for
vaccine candidates.
○ Even though it is constantly mutating, it is not mutating rapidly, as compared to the flu virus--
needs an updated vaccine every year, to keep up with the new strain.
• SARS-CoV-2 has relatively low genetic diversity (less RNA progeny) compared to other viral
pathogens. -> Varying strains should not impede development of vaccine.
• False positive or false negative results to a COVID diagnostic tests?
○ Nasal swab or saliva test by qPCR.
○ Blood test for antibodies.
○ False (-): not enough material collected, sampling/storage problems, lack of test sensitivity
○ False (+): contamination, cross-reactivity picking up false signal (RAs handling sample are
positive), etc.
• Antibody response happens a week after infection, and it's activity is prolonged even after virus
symptoms/infections are gone.
• Long-haulers: ppl who have been showing symptoms for many months-- prolonged symptoms.
SARS-CoV-2 is a (+) ssRNA virus whose viral RNA DECs overtime due to production of
memory B cells (propose an immune response when exposed again). The virus is
constantly mutating, but we don’t know if those mutations are deleterious, nor is it
mutating rapidly. The virus has LOW genetic diversity; dif strains will not impede vaccine
development. False (-) are due to not enough collection, sampling/storage problems, test
lacking sensitivity. False (+) are due to contamination, cross-reactivity picking up a fake
signal.
