Why you now need to know about antibodies and sero-prevalence
As the Tokyo Olympics take place, the rampant Delta variant of the SARS-CoV-2 virus has been described by a UK government microbiologist as the fastest, fittest and most formidable adversary yet.
Meanwhile, Nature journal reports that a recent study in China that tracked some of the first people there to become infected with the Delta strain found that the ‘viral load’ they carried was up to 1,260 times higher than those with the original SARS-CoV-2 strain in 2020.
A person’s viral load is a measure of the density of virus particles found in his or her body. This makes them potentially able to exhale much higher concentrations of viral particles into the air. Coupled with the Delta strain’s faster replication rate, it helps to explain the non-social causes of the surge in transmissions around the world even as vaccination rates rise.
Here are some figures up to the third week of July from three countries with some of the highest vaccination rates:
Singapore recorded 75 percent of new infections comprising vaccinated people who were asymptomatic
In Israel, 60 percent of Covid-19 patients who required hospitalisation had been vaccinated. Israeli government data shows the Pfizer/BioNTech vaccine appeared 41 percent effective at halting symptomatic infections
In the UK, 22.8 percent of 3,692 hospital patients infected with the Delta variant had been fully vaccinated
It should be noted that of the patients above, those who experienced severe symptoms were unvaccinated.
As developed countries reopen mass air travel and sea cruises, virologists and epidemiologists are now concerned about tourists spreading the virus to unvaccinated locals as well as among themselves.
Comprehensively tracking virus transmission and correlating it with vaccination rates and efficacy will take on greater significance in this new phase of the pandemic. This involves testing people for SARS-CoV-2 antibodies which the body produces in response to an infection.
(For a brief guide to antibody tests, antigen tests and their uses, click here)
ImmuSAFE COVID+ is a novel, lab-based biochip test for Covid-19 developed by the functional proteomics company Sengenics.
It can be used to address four fundamental questions under the scenarios below:
Scenario 1: Suspected Covid-19 infection
Confirm with high accuracy whether an individual has been infected with the SARS-CoV-2 virus.
Determine whether the level and target location of the antibodies in an individual are likely to offer protectivity (more on which, below).
Scenario 2: Post-vaccination
Confirm whether an individual has generated a sufficiently strong immune response to the vaccine to confer protection.
Retesting to confirm the status of ongoing protection and evaluating whether a booster vaccine is required.
For accurate detection of the presence of the virus, ImmuSAFE includes multiple domains of SARS-CoV-2 Nucleocapsid and Spike proteins, including both full-length and numerous truncated versions.
ImmuSAFE utilises Sengenics’ patented KREX protein-folding technology to correctly preserve all the structures of the SARS-CoV-2 virus or epitope that are used by antibodies to bind themselves to it. 
ImmuSAFE can also differentiate whether observed antibody responses are due directly to the vaccine or to prior SARS-CoV-2 exposure.
KEY APPLICATIONS IN MORE DETAIL
ImmuSAFE can be utilised for vaccine clinical trials or sero-prevalence research studies that measure the presence of antibodies in a population group.
Population antibody profiling for sero-prevalence research
The target epitope of antibodies produced following infection exhibit a significant level of diversity across a population. ImmuSAFE provides a more accurate determination of sero-prevalence by targeting multiple domains of SARS-CoV-2 proteins.
 These are known as conformational and linear sites or, roughly, epitopes.
Determine the protective quality and quantity of antibodies produced
Some individuals produce antibodies that target locations which are neutralising (protective), whereas others produce non-neutralising antibodies. ImmuSAFE can be used to identify individuals who have high titres of potentially neutralising antibodies against SARS-CoV-2.
Enable quantitative assessment of antigen-specific response by individuals in vaccine trials
Investigate SARS-CoV-2 specific immunoreactivity in patients and healthy individuals for vaccine development, safety and efficacy determination in clinical trials.
Data from ImmuSAFE tests so far enable three major conclusions to be inferred:
There is a wide variation in antibody titres across SARS-CoV-2 infected individuals
There is a high degree of variation in patient-specific antibody responses to the different domains of SARS-CoV-2 proteins
Wider coverage of target epitopes leads to increased sensitivity and specificity
ImmuSAFE can be used in Covid-19 test centres in multiple existing facilities, offering numerous potential solutions for government agencies or businesses that rely on real-time knowledge of infections in individuals — such as aviation, logistics, tourism and industrial sectors.
Neogenix Laboratoire Sdn Bhd is licensed to provide laboratory testing for the ImmuSAFE COVID+ Biochip. It is a 60 percent owned subsidiary of HS Bio Sdn Bhd, a wholly-owned subsidiary of Hong Seng Consolidated Berhad.