The test uses the interaction between viral protein-receptor protein to
mimic the virus infection of a live cell, which is monitored by a
chromogenic reaction.
When there are neutralizing antibodies in the patient sera, they will
block the specific protein-protein interaction and hence reducing the
chromogenic reaction, mimicking the virus neutralization process.
Most COVID-19 antibody test kits in the market evaluate the ability of a
patient to generate antibodies bind virus, such as IgG, IgM, or total
antibody, but they do not tell whether such antibodies can neutralize
the virus and break virus life cycle, which is essential for a person's
acquired immunity against the pathogen. Our kit detects the antibodies
that have blocking/neutralization function. Therefore, it is a better
measure of potential resilience to re-infection.
Traditionally, the presence of neutralizing antibodies are detected by
virus neutralization test(VNT). Conventional virus neutralization tests
require live viruses and cells, biosafety containment facilities, highly
skilled operators, are less sensitive, and take days to obtain results.
Our cPass™ test does not involve live virus and cells and can be
used in any lab, except the test sample itself is infectious and need
biosafety level 2 or 3 (BSL2, BSL3) labs. The operation steps are much
more straightforward and only take 1 hr to run.
The standard virus neutralization test (VNT) uses live virus to infect
human cells. Anything that can inhibit the infection can be recognized
as a neutralization agent. This method has been the gold standard.
However, the process is tedious (takes days) and requires using high
level safety lab facility (biosafety level 3). Therefore, the assay is
expensive and cannot be widely used.
Another approach is pseudovirus neutralization test, it is specific and
can be performed in BSL2 labs. However, it is still dependent on live
cells and virus and is hard to commercialize.
Our kit measures protein-protein interaction which does not require live
cells or virus. Our kit can be used in any laboratories unless you are
handling health hazardous samples, which requires BSL2 or BSL3 based on
local regulation. It can also amenable to automation.
When using as serology test on patients, if the cPass™ test gives
a positive result, it means the person most likely has been infected by
the virus in the past, indicating potential immunity against the virus.
With this serology test, large amount of data can be provided for
epidemiologic study.
In the society or community, this is the most practical way to evaluate
the level of "herd immunity".
It can be used to test whether an animal or a pet has been infected by
COVID-19 virus. In zoology studies, this can be used to find out the
animal intermediate host of COVID-19.
In vaccine development, it can be used to evaluate the ability of
vaccines to generate such antibodies in vaccine immunized population,
and to measure how long the neutralizing antibodies exist.
In clinical therapeutics, this kit can be used to identify which donor
has the functional neutralization antibodies, and with confirmed
negative qRT-PCR that shows viral clearance, the individuals might be a
qualified volunteer to donate serum for passive therapeutics to save
seriously ill patients.
This kit can also be used to screen therapeutic antibodies, which are
engineered to block the interaction between RBD and ACE2.
As our kit is species-independent, customers can use our kit to screen
antibodies derived from any host, such as mouse, rabbit, human, or
llama.
cPass™ can also be used by researchers to identify the
intermediate host between bat and human, which is a critical missing
link when we try to trace the origin of the pandemic.
cPass™ is useful to screen animals in contact with human, which
helps to build guidelines on which animal may contract SARS-CoV-2 and
how should such risk be mitigated.
The cPass™ kit is a serology test that checks the neutralizing
antibody against SARS-Cov-2 in response to infection. It should not be
used to diagnose acute SARS-CoV-2 infection, as the antibodies could not
be generated in a short time period.
On the other hand, an individual with past infection but already have
virus clearance may still have neutralizing antibody as acquired
immunity.
Diagnostic tests are molecular tests that mainly check genetic material
from the virus itself, usually by Quantitative Reverse Transcription
Polymerase Chain Reaction (qRT-PCR), to diagnose active infections
through nasal swab, throat swab, saliva, etc.
No, our test requires a simple ELISA plate reader that is typically
available in almost all clinical diagnostics labs. We are adapting it to
run on some popular automated ELISA systems.
