Details of SARS-CoV-2 (COVID-19) ANTIGEN - RAPID
What is SARS-CoV-2 (COVID-19) ANTIGEN - RAPID?
The SARS-CoV-2 Rapid Antigen Test is a reliable, rapid chromatopgraphic immunoassay for the qualitative detection of specific antigens of SARS-CoV-2 present in the human nasopharynx.
This test is an aid in detecting antigen from the SARS-CoV-2 virus in individuals suspected of COVID-19. This product is strictly intended for professional use in the laboratory and Point of Care environment.
SARS-CoV-2: An overview.
Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is an enveloped, single-stranded RNA virus of the family Coronaviridae. Coronaviruses share structural similarities and are composed of 16 nonstructural proteins and 4 structural proteins: spike (S), envelope (E), membrane (M), and nucleocapsid (N). Coronaviruses cause diseases with symptoms ranging from those of a mild common cold to more severe ones such as Coronavirus Disease 2019 (COVID-19) caused by SARS-CoV-2 2,3.
SARS-CoV-2 is transmitted from person to person primarily via respiratory droplets, while indirect transmission through contaminated surfaces is also possible4-7. The virus accesses host cells via the angiotensin-converting enzyme 2 (ACE2) receptor, which is most abundant in the lungs8,9.
The incubation period for COVID-19 ranges from 2 - 14 days following exposure, with most cases showing symptoms approximately 4 - 5 days after exposure4,10,11. The spectrum of symptomatic infection ranges from mild (fever, cough, fatigue, loss of smell and taste, shortness of breath) to critical12,13. While most symptomatic cases are not severe, severe illness occurs predominantly in adults with advanced age or underlying medical comorbidities and requires intensive care. Acute respiratory distress syndrome (ARDS) is a major complication in patients with severe disease. Critical cases are characterized by e.g., respiratory failure, shock and/or multiple organ dysfunction, or failure12,14,15.
Definite COVID-19 diagnosis entails direct detection of SARS-CoV-2 RNA by nucleic acid amplification technology (NAAT)21-23. Direct detection of the virus through antigen testing is an alternative to NAAT24. Serological assays, which detect antibodies against SARS-CoV-2, can contribute to identifying individuals, which were previously infected by the virus, and assessing the extent of exposure of a population. They might thereby help to decide on the application, enforcement, or relaxation of containment measures25.
Upon infection with SARS-CoV-2, the host mounts an immune response against the virus, including the production of specific antibodies against viral antigens. Both IgM and IgG have been detected as early as day 5 after symptom onset26,27. Median seroconversion has been observed at days 10 - 13 for IgM and days 12 - 14 for IgG28-30, while maximum levels have been reported at weeks 2 - 3 for IgM, weeks 3 - 6 for IgG, and week 2 for total antibody26-32. Whereas IgM seems to vanish around week 6 - 733,34, high IgG seropositivity is seen at that time26,33,34. While IgM is typically the major antibody class secreted to blood in the early stages of a primary antibody response, levels and chronological order of IgM and IgG antibody appearance seem to be highly variable for SARS-CoV-2. Anti-SARS-CoV-2 IgM and IgG often appear simultaneously, and some cases have been reported where IgG appears before IgM, limiting its diagnostic utility27,28,30,35,36.
After infection or vaccination, the binding strength of antibodies to antigens increases over time - a process called affinity maturation37. High-affinity antibodies can elicit neutralization by recognizing and binding specific viral epitopes38,39. In SARS-CoV-2 infection, antibodies targeting both the spike and nucleocapsid proteins, which correlate with a strong neutralizing response, are formed as early as day 9 onwards, suggesting seroconversion may lead to protection for at least a limited time35,40-43.
The benefit of having a SARS-CoV-2 antigen test available:
The SARS-CoV-2 virus causes respiratory tract infection. It is transmitted mainly via respiratory droplets after close contact, and primary viral replication is presumed to occur in the mucosal epithelium of the upper respiratory tract (nasal cavity and pharynx).2 At these locations viral load peaks within the first week after symptom onset, and then declines.3
A SARS-CoV-2 antigen test detects the presence of the SARS-CoV-2 virus from part of the upper respiratory tract swab specimens by identifying a nucleoprotein that is carried by the virus. The test identifies current infection during the acute phase of COVID-19, while the virus is still present in large quantities in the respiratory tract.
Features and benefits of the SARS-CoV-2 Rapid Antigen Test:
Besides laboratory PCR testing, antigen assays can also be offered as rapid testing in near-patient settings. The SARS-CoV-2 Rapid Antigen Test is a rapid chromatographic immunoassay intended for the qualitative detection of specific antigens of SARS?CoV?2 present in nasopharyngeal or combined nasopharyngeal/oropharyngeal samples. This test is intended to detect antigen from the SARS?CoV?2 virus in individuals suspected of COVID?19. This product is strictly intended for professional use in laboratory and Point of Care environments. Similar to laboratory instruments, it detects a SARS-CoV-2 antigen, the nucleoprotein. It can therefore be used to assess whether a person is infected with SARS-CoV-2 by providing a qualitative result showing colored bands indicating the presence of SARS-CoV-2 antigens.
The SARS-CoV-2 Rapid Antigen Test enables fast decision making e.g. whether patients need to be put in quarantine, reducing the risk of further spreading. In addition to that, it allows for screening of individuals after confirmed exposure to a SARS-CoV-2 infected person or individuals at risk of exposure such as healthcare workers.
The SARS-CoV-2 Rapid Antigen Test allows for decentralized testing at the point of care and helps to expand the range and quantity of direct virus testing into otherwise inaccessible locations. Rapid point of care testing can sometimes be the only viable option if lab testing is not sufficiently available. In addition to that, the SARS-CoV-2 Rapid Antigen Test is an instrument-free test, allowing testing in rural/ low-infrastructure areas.
The benefits of the SARS-CoV-2 Rapid Antigen Test in short:
Getting a quick result within 15-30 minutes – no need for a follow-up appointment to discuss the result
Easy handling which does not require specific training
No instrument required
Allowing decentralized testing or access to testing in areas where laboratory testing is not available