Copy of Wajnberg et al Quiz, Copy 3 PDF

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quiz for dr David Camerini...

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Wajnberg et al Quiz Type your name: Type your UCI 8-digit Student ID: Make a copy of this document (File: Make a copy). Add your answers to the column on the right. Use the word count tool (Tools > Word Count) to judge the length of your answer. Download and submit as a pdf. Do not paste into a new document, change the formatting of this page or go onto a second page - it will affect grading and reduce your points. You may use the abbreviations SARS-CoV-2 and COVID-19 without defining them. Questions

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1. How does figure 1B support the hypothesis that COVID-19 patient antibody titers to the SARS-CoV-2 spike protein (S) did not vary substantially from 4 April 2020 to 5 October 2020, despite the changing number of patients tested? Please answer in 125 of your own words or less. (3 pts)

Figure 1B shows that, of all positive patients, the percent of individuals with antibody titers above 1:320 fluctuated around 90%. Although the number of patients getting tested varies each day, this percentage does not seem to be affected by the sample pool. The fluctuation ranges from 80% to 100%, which is considerably a small gap. Therefore, it indicates that there is no significant difference in antibody titers of COVID-19 patients tested from 4 April 2020 to 5 October 2020.

Your submitted document should still be 14” high and be a copy of the original. A change in the table, font or document size means it was copied and completed by some other method than File: Make a copy in Google Docs and will lose points.

2. How does figure 2A support the hypothesis that COVID-19 patient ELISA endpoint antibody titers to SARS-CoV-2 S are positively correlated with patient SARS-CoV-2 neutralization ID50 values? Please answer in 100 of your own words or less. (3 pts)

Figure 2A shows that, generally, as the ELISA endpoint titer(x-axis) increases from 1:80 to 1:2880, the 50% inhibitory dilutions (ID50) values (y-axis) increase as well. Even though there is some variability, the geometric mean (red bar) clearly supports this trend. For instance, antibody titers of 1:320, 1:960, and >1:2880 have neutralization ID50 of 1:30, 1:75, and 1:550 respectively. This implies that more neutralization titers are positively correlated with spike-binding titers.

3. Compare figures 3B and 3F. Please describe what each figure shows including what is measured and the patient group shown. You should include the initial endpoint antibody titer shown in each graph at day 30, the trends in the change of the value at day 82 and 148, the statistical significance of the changes and the approximate final endpoint titer on day 142. Please answer in 240 of your own words or less. (5 pts)

Both figure 3B and 3F show COVID-19 neutralizing antibody titers of symptomatic patients measured around 30 days-, 82 days-, and 148 days after COVID-19 symptoms. Blood was drawn from patients who experienced mild-to-moderate COVID-19 symptoms, and detection of antibodies against the spike protein was performed for all samples. Figure 3B showed results for a group of patients with initial titer above 1:2880 (first screening), which was classified as high antibody level, while figure 3F showed antibody titers of patients with initial titer of 1:80, which was considered very low antibody level. It was hypothesized that the level of antibodies should decline over time. The antibody trends observed for each group were interestingly different. For patients of initial high titer (figure 3B), the antibody titer started high (on day 30) and slightly declined over time to around 1:1000 and 1:900 on day 82 and day 148 respectively, which was expected. For patients of the lower initial antibody titer range 1:80 (figure 3F), the antibody level increased from day 30 to day 82 (from 1:80 to about 1:160), but then dropped from day 82 to day 148 (1:80), which was not as predicted. However, it supports the observation that seroconversion in mild COVID-19 cases took longer time to produce and mount. Overall, these analyses showed that while the antibody level from patients with initial high titer declined over time, that of the patients with initial low titer increased at some point and then decreased....