CBP’s response to SARS-CoV-2/COVID-19 Pandemic
Cape Bio Pharms is responding to the SARS-CoV-2 Pandemic in a variety of ways.
The best way to manage a pandemic is with early detection and/or prevention. To this end, Cape Bio Pharms is producing SARS-CoV-2 Spike S1 reagents consisting of various regions of this huge glycoprotein attached to various fusion proteins. In R&D are a range of antibodies against the RBD, as well as anti-Human IgG/IgM. Test kit manufacturers can utilise these proteins to create rapid diagnostic test kits to detect antibodies against the virus within blood samples.
SARS-CoV-2, the virus that originated in Wuhan, China, is now spreading at an alarming rate worldwide. Since it's first appearance and identification in January 2020, it has spread to at least 177 countries and as of June 20 July 2020, there have been 14,348,858 confirmed cases of COVID-19, including 603,691 deaths, reported to WHO. This number is, however, not a true representation as many cases are asymptomatic and go undetected. Asymptomatic cases are as infectious and contribute to the spread of the virus. Symptoms of the disease, termed COVID-19, include fever, cough, shortness of breath(dyspnoea), headache and pneumonia. Symptoms occur within 2-14 days of infection.
The most likely natural reservoir for the SARS-CoV-2 virus according to WHO is bats1. It is assumed to have jumped from animals (bats/pangolins) to humans as the similarity between the bat/pangolin viruses and the viruses extracted from cases has high sequence similarity2.
The best way to manage a pandemic is with early detection and/or prevention. There are currently various methods for detection of SARS-CoV-2 infection. For a great Science article reviewing this, check out: https://www.the-scientist.com/news-opinion/how-sars-cov-2-tests-work-and-whats-next-in-covid-19-diagnostics-67210
The WHO has adopted an RT-PCR based detection method aimed at amplifying the E gene. As the viral genome is in RNA form, it must first be reverse transcribed into cDNA before PCR can determine the presence of a specific sequence. There are other forms of PCR tests available. The CDC is currently also using rRT-PCR as detection method, however they are using primers to amplify the N1, N2 and N3 genes. They also have an ELISA based detection method but say that this is only effective 21 days after infection. There is a definite need for PCR based detection methods for confirming active infections. Another type of test is serology testing. This detects antibodies (IgM/IgG) within patient blood samples to confirm those that have had an immune response to the virus. Once someone has recovered from the infection, this is a useful tool to determine who has been exposed to the virus.
To this end, Cape Bio Pharms is producing SARS-CoV-2 Spike Protein 1 reagents consisting of various regions of this huge glycoprotein. The virus contains Spike Proteins on the outside that are involved in cellular entry through the ACE-2 receptor2. In addition, we have in research and development a library of antibodies against the RBD, as well as anti-Human IgG and anti-Human IgM.
The antibodies and antigen have been immobilized onto lateral flow devices to create protein diagnostic test kits. We are collaborating with local lateral flow device manufacturers who are implementing our proteins onto their test kits. These tests involve conjugating S1 and RBD antigens to gold as well as immobilising anti-Human IgM and anti-Human IgG to the membrane. Fingerprick blood is then place on the device and the IgM and IgG antibodies will 'pick up' the SARS-CoV-2 antigens within the conjugate pad and flow across the membrane. IgM antibodies against the virus are an sign of early stage infection, while IgM forms later in the infection timeline. These tests are currently in validation phase with local regulatory authority in South Africa.
Our test kit 2.0, an antigen test kit that can detect virus particles within fingerprick blood, is in R&D. However it needs to be determined at what stage in infection this would be possible as well as if viral titres are high enough/ this test is specific enough for this.
Please refer to the 'contact us' page and contact Tamlyn if you have enquiries about our response to COVID-19 or if you would like more information.
- Organisation, W. H. Report of the WHO-China Joint Mission on Coronavirus Disease 2019 ( COVID-19 ). 2019, (2020).
- Zhou, P. et al. A pneumonia outbreak associated with a new coronavirus of probable bat origin. Nature 2019, (2020).