Watch this certified on-demand webinar to learn about the role of serology in the clinician’s toolbox for the administration of COVID-19
Dr. Sarah Jenks, Consultant Biochemist at NHS Lothian
SARS-CoV-2, the causative agent of COVID-19, has led to a global pandemic. Serology assessments can be used for sensitivity to seroprevalence, voluntary screening for immunization tests and regenerative plasma donations, as well as to predict vaccine-induced infectivity or immunity.
Several commercially available SARS-CoV-2 immunoassays have been evaluated for their sensitivity and further studies have evaluated the role of the antigen target in its ability to assess protection against relapse.
This on-demand webinar features Dr Sara Jenks, Consultant Biochemist at NHS Lothian, Elizabeth Furrie, Clinical Scientist and honorary lecturer at NHS Tayside, and Frauke Muecksch, Postdoctoral Associate at Rockefeller University, who ‘explain why public health strategies are going ahead. based on the ability to respond a) how the circulation of antibody levels specific to each viral antigen changes over time following a natural infection and b) what serological assays provide the best predictor of immune resistance.
Attendees are entitled to PACE credits from ASCLS and / or ACCENT credits from the AACC.
Read on for the main events of the live Q&A session or sign up to watch the webinar at any time that suits you.
Q: Could you clarify by neutralizing antibodies, do you mean IgM, IgG, or both?
FM: This would be every antibody class. The tests we use to work out neutralization are not to differentiate between the antibodies. For example, the sample contains IgA or IgM – both would be measured.
Q: Vaccines currently under development will have a 60% efficacy. What does this mean and how is the effectiveness measured?
SJ: I am not in the best position to comment on how the effectiveness of vaccines has worked out. I know that there has been a lot of discussion in papers, certainly within the UK, about how they explain the effectiveness of vaccination and that it may be more of a reduction in symptoms than a preventing people from becoming infected. However, it just raises the question of how these antibody tests might play a role in trying to find out who responded and who is and is not in need of a vaccine. , especially if the resulting vaccines reverse this type of developmental wave. out to be somewhat non-optical. In terms of how these tests fit into that kind of process, I think that is very much explained and these tests may have a place in that area.
Q: What exactly does serology play in the diagnosis of SARS-CoV-2 disease, and if you were to choose one assay, which one would you choose and why?
SJ: In terms of using the test around a primary diagnosis, I think all available antibody tests do so largely because most of them are very sensitive. , picking up antibodies early, around the time of actual diagnosis. I think you could use any of the tests for that. I wonder where they differ in performance as the time from disease increases and we start to see very different results as we have shown with the cohort people. which we have been pursuing.
Q: What is the structure of the neutralizing antibody?
FM: Most neutralizing antibodies appear to bind to the receptor binding domain of the spike region, which makes sense as this is the region where IgGs still bind to its receptor on the cells. Some finds we find again, the VH3 53 and 66 concentrations of RBD neutralize antibodies. A difference we can see to the human antibody repertoire is that the SARS-2 antibodies appear to have fewer mutations.
Q: What value do you think an IgM-only assay could offer, given that early seroconversion to IgG is frequent and the existing data show that IgM is less sensitive than total IgG in patients?
EF: Cineatics like IgM and IgG come up almost simultaneously. However, we have a subset of patients where we routinely receive negative swabs for PCR but we are convinced from the indications that they may have SARS-CoV-2 infection. The idea is that the IgM may be able to differentiate early infection faster than the IgG. The evidence is not yet available but you must be aware that the MRCs available to date are not very specific or sensitive. As MRCs grow, we may find that they are better used, but that is certainly where we think they may be useful in early infection before IgGn comes when we cannot get positive results. get a swab.
Q: Have you noticed any difference between the asymptomatic disease profiles and those showing symptoms of COVID-19?
FM: In terms of neutralization, we see differences. I’m talking about other cohorts here, where people with stronger symptoms developed a higher neutral crisis. This study was performed on patients with mild symptoms and the corrections were less clear in this case.
Watch this on-demand webinar for more information on the role serology plays in the clinician’s toolbox for COVID-19 administration >>