New Vaccination Strategy Developed That Could Prevent Future Coronavirus Outbreaks


SciTechDaily 08 October, 2021 - 09:00am 7 views

Assay to assess and quantify presence of RBD-directed antibodies against SARS-CoV-2 following vaccination

News-Medical.Net 08 October, 2021 - 02:20pm

We use cookies to enhance your experience. By continuing to browse this site you agree to our use of cookies. More info.

Currently rated 1.0 by 1 person

Coronavirus disease 2019 (COVID-19) caused worldwide health and economic crises. While the development and mass administration of vaccines has successfully halted the progression of the disease in some countries, many are still struggling with the disease burden.

The rise of variants of concern, such as the Delta variant that can evade both vaccine-induced and natural immunity, is a worry to all countries. The need for highly specific and sensitive assays that can quantify immune activity against COVID-19 infection is necessary for vaccine development, monitoring the effects of treatment, the levels of immunity in the population, and identifying the effectiveness of vaccines against new variants.

To this extent, researchers from Roche Diagnostics have been testing a new assay known as the Elecsys assay. A preprint version of the study is available on the medRxiv* server while the article undergoes peer review.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) contains four structural proteins, and the vast majority of immune responses target either the nucleocapsid (N) or spike (S) proteins. The spike protein is the target of most tests and vaccines, as it is key for the organism's pathogenicity.

The S1 subunit contains a receptor-binding domain (RBD) that binds to angiotensin-converting enzyme 2 (ACE2) to allow viral cell entry. The N-terminal of the S2 subunit is responsible for membrane fusion. IgM, IgG, and IgA can normally be detected two weeks after the onset of symptoms.

The Elecsys assay is an automated, high-throughput assay that focuses on antibodies against the RBD of the S protein. The scientists tested the assay by detected antibodies produced in individuals vaccinated against SARS-CoV-2 using the Moderna mRNA vaccine.

The researchers used samples from participants involved in the initial trials for the Moderna vaccine, including samples from healthy individuals between 18 and 55 years old who had received two doses of the vaccine 28 days apart at doses of either 25 or 100 ug.

To compare the antibody responses to those produced from previously convalescent individuals, samples from those confirmed infected with PCR tests were taken and analyzed using the Elecsys assay. These samples were all taken from individuals with both mild and severe courses of the disease. Samples were gathered from individuals in Switzerland, Germany, and Ukraine.

In total, 30 vaccinated individuals were examined, 15 who had received 25ug doses and 15 who had received 100ug doses. The Elecsys assay showed anti-RBD antibodies increase over time, and the antibodies were first detectable at day 15, suggesting seroconversion occurred some point before this.

Two individuals from the 25ug group did not show results at this time and did not develop significant antibody concentrations until day 29. The 100ug group showed a very similar anti-RBD response, with less spread between individuals.

Natively infected individuals developed a more heterogeneous antibody response - not unusual, given the immune system would have been exposed to multiple different proteins and not homogenous RBD proteins.

The Elecsys assay showed similar results to comparable assays, with statistical analysis showing a strong correlation between the tests. All positive results on the control assay received a positive result using the Elecsys assay, with a few samples showing a negative control result but a positive Elecsys result.

The authors highlight the benefit this new assay could bring in the fight against COVID-19. The assay successfully allowed the changes between dosage groups over time to be monitored and strongly correlated with the control assay.

The study showed seroconversion in all individuals who had received the vaccine after a short amount of time, that those who received the 100ug dose showed higher concentrations of anti-RBD antibodies compared to those who received the 25ug dose, and that the Moderna vaccine can produce higher levels of antibodies than seen in individuals who had become immune through infection.

medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behaviour, or treated as established information

Currently rated 1.0 by 1 person

Posted in: Medical Science News | Medical Research News | Disease/Infection News

Tags: ACE2, Angiotensin, Angiotensin-Converting Enzyme 2, Antibodies, Antibody, Assay, Cell, Coronavirus, Coronavirus Disease COVID-19, Diagnostics, Enzyme, Immune System, immunity, Membrane, Protein, Receptor, Respiratory, SARS, SARS-CoV-2, Severe Acute Respiratory, Severe Acute Respiratory Syndrome, Spike Protein, Syndrome, Vaccine

Sam completed his MSci in Genetics at the University of Nottingham in 2019, fuelled initially by an interest in genetic ageing. As part of his degree, he also investigated the role of rnh genes in originless replication in archaea.

Please use one of the following formats to cite this article in your essay, paper or report:

Hancock, Sam. (2021, October 08). Assay to assess and quantify presence of RBD-directed antibodies against SARS-CoV-2 following vaccination. News-Medical. Retrieved on October 08, 2021 from

Hancock, Sam. "Assay to assess and quantify presence of RBD-directed antibodies against SARS-CoV-2 following vaccination". News-Medical. 08 October 2021. <>.

Hancock, Sam. "Assay to assess and quantify presence of RBD-directed antibodies against SARS-CoV-2 following vaccination". News-Medical. (accessed October 08, 2021).

Hancock, Sam. 2021. Assay to assess and quantify presence of RBD-directed antibodies against SARS-CoV-2 following vaccination. News-Medical, viewed 08 October 2021,

In this interview, News-Medical talks to Dr Yuning Chen, about the work he does with Sino Biological and how they have adapted their research & development to the COVID-19 pandemic.

In this interview, News-Medical talks to ZwickRoell UK about materials testing in the pharmaceutical and medical industry.

News-Medical speaks to Dr. Yana Vinogradova about her latest research into menopausal hormone therapy (MHT) and its unassociated risk to dementia.

News-Medical.Net provides this medical information service in accordance with these terms and conditions. Please note that medical information found on this website is designed to support, not to replace the relationship between patient and physician/doctor and the medical advice they may provide.

Owned and operated by AZoNetwork, © 2000-2021

london: Covid infection during pregnancy impacts immune system of foetus: Study - Times of India

Times of India 08 October, 2021 - 02:38am

We use cookies and other tracking technologies to provide services while browsing the Website to show personalise content and targeted ads, analyse site traffic and understand where our audience is coming from in order to improve your browsing experience on our Website. By continuing to use our Website, you consent to the use of these cookies and accept our Privacy terms. If you wish to see more information about how we process your personal data, please read our Cookie Policy and Privacy Policy

Copyright © 2021 Bennett, Coleman & Co. Ltd. All rights reserved. For reprint rights: Times Syndication Service

Health Stories