An article by Patrick J Bouic and Leo Maritz et al published in the May 2022 edition of Bioanalysis investigated the development and validation of SARS-CoV-2 serology assays for both serum and dried blood spot (DBS) samples. The DBS samples were collected with hemaPEN® microsampling devices. The paper is entitled “Validation of high-throughput, semiquantitative solid-phase SARS coronavirus-2 serology assays in serum and dried blood spot matrices.”
The study showed that the hemaPEN dried blood samples correlated well with the traditional serum samples. Furthermore, the assays were able to measure IgG, IgA, IgM antibodies and neutralizing antibodies with high diagnostic sensitivity and specificity.
There were no reported increases in Covid-19 safety measures other than the continued recommendation to get vaccinated against the virus and its variants – a measure that has proven to be very effective. Some health agencies recommended that people take extra care to protect against the latest “Covid-19 wave” as people spend more time indoors during the winter season.
The third year of the Coronavirus Pandemic is drawing to a close, and research on SARS-CoV-2 continues as scientists seek to understand how the virus and its variants affect us. They hope new insights will help physicians treat Covid-19 and related viral infections. For example, research institutions are continuing to develop tools to understand the serological landscape of Covid-19 antibodies.
This work includes studies that detect and monitor neutralizing antibodies found in dried blood samples collected remotely by people who have been exposed to the virus. Such studies include those who have recovered from Covid-19 infections and those who have received Covid-19 vaccines.
Research centers at Stanford University and the National Institutes of Health (NIH) have used microsampling devices to collect dried blood samples for their infectious disease serology studies. Some serology studies have paired dried blood microsamples with analytical tools like the SIMOA (recently reviewed in a previous blog).
Throughout the pandemic, the use of remote microsampling solutions such as DBS and volumetric microsampling devices have proven to be effective in screening populations, while also keeping them safe at home. Remote devices that gained favor early in the pandemic as effective tools that helped people safely continue participating in studies have become increasingly popular.
In March 2022, the NIH reported their researchers were working on a new study using the Mitra® device to measure rates of undiagnosed Covid-19 in households with a child who has mitochondrial disease. This important research will be covered in a future blog.
Bouic and Maritz et al commented that the serological landscape of Covid-19 continues to rapidly evolve and the need to continue monitoring immunity and vaccine efficacy is paramount. The group chose to use the hemaPEN® microsampling device to develop solid phase immunoassays for measuring raised IgG, IgM and IgA antibodies, as well as neutralizing antibodies, to SARS-CoV-2.
A reason they reported for choosing hemaPEN over DBS cards was due to the limitations of DBS, such as volume variability, hematocrit-based biases, and risk of cross contamination. The volumetric sampling enabled by the hemaPEN, however, overcomes the limitations of DBS while capitalizing on its benefits, such as excellent stability of antibodies in dried blood and enabling remote, decentralized sample collection.
The researchers validated a SARS-CoV-2 serology serum assay for IgG, IgM, IgA and nAbs, which showed high DSn, DSp and low cross-reactivity with patients that had chronic inflammation. The assay correlated well with the hemaPEN samples and worked well as a “gold standard” in vitro viral neutralization assay. The utility of the assay would be suitable for Phase 4 clinical trial monitoring of vaccine efficacy (including long-term post-marketing antibody level surveillance).
As the Covid-19 Pandemic continues, it is important that we also continue to develop new tools to effectively monitor populations. Capillary blood sampling using remote microsampling devices such as the hemaPEN and Mitra devices are helping researchers demonstrate that highly correlative results can be obtained compared to blood taken from standard phlebotomy. This opens new avenues for remote research and hybrid clinical trials, as well as decentralized population studies.
This article was summarized for our readers by James Rudge, PhD, Neoteryx Technical Director. This is curated content. To learn more about the important research outlined in this blog, visit the original article in Bioanalysis.
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