Covid-19 Diagnostic Market

US accused China of sending low-quality and even counterfeit coronavirus antibody testing kits

India’s ICMR halts the use of rapid testing kits to detect coronavirus that were sourced from China.

Authorities in Spain, Turkey, and the Netherlands reject Chinese-made testing kits and medical masks which were found to be below standard or defective.

UK discards millions of millions of coronavirus test kits purchased from China. Professor Sir John Bell, coordinator of coronavirus testing for Public Health England, stated that the antibody tests are not reliable.

Roche Coronavirus Antibody Test Wins FDA Approval for Emergency Use

Here is the list of FDA-approved authentic manufacturers of Covid-19 diagnostic kits.

Key companies approved for RT-PCR for nasal-swab-based tests

 

Key companies approved for blood-sample-based Serology tests

 

The COVID-19 Diagnostic Market is Dominated by RT-PCR Tests But Serology-based Tests are Catching up Fast
While there are no FDA-approved diagnostics for COVID-19, the FDA, on March 16, 2020, relaxed the regulations around COVID-19 diagnostic in order to expedite the availability of testing by introducing EUA policy. Diagnosing viral infections currently relies on two major methodologies: reverse-transcription polymerase chain reaction (RT-PCR) and serological immunoassays that detect viral-specific antibodies (IgM and IgG) or antigens. Though the agency initially had only included RT-PCR-based test in its protocols, later, it also included serological tests in the diagnostics ambit.

The Advent of Antigen Detection Based Test Kit is Expected to Change the Dynamics of COVID-19 Diagnostic Market

While RT-PCR-based testing is the most common method for the identification of infectious cases, the serological assays and rapid test kits for antigen detection could also play an important role in diagnosis, research, and surveillance. Technically, the RT-PCR type of test is more accurate than the serological version, but the serological test can have comparable specificity and may offer advantages in terms of lower cost, faster turnaround, and greater portability.

Even if the COVID-19 diagnostic market is dominated by RT-PCR-based technology, the complexity of the test, time duration and resource availability have been the key concerns, which has been limiting its scalability at the larger scale.

RT-PCR requires high-quality nasopharyngeal swabs containing sufficient amounts of viral RNA. This can be a challenge because the amount of viral RNA not only varies significantly between patients, but it can also vary within the same patient depending on the timing of the test and the start of the infection. This increases the possibility of inaccurate test results. Moreover, this type of test is not easy to carry out during a global pandemic with potentially millions of people to test, leading to delays in testing as medical facilities become overwhelmed with requests.

While Both the Methods Have Their Limitations, When it Comes to Faster Turnaround and Wide Scale Detection Program, Serology-Based Tests Seem to be the More Feasible Option

Generally, the RT-PCR-based tests are time consuming, with average test taking from a few hours to couple of days to produce the result. Here, on the other hand, IgG/IgM serological tests provide some advantages over RT-PCR, due to its easy procedure and quicker turnaround time (taking between 5 to 20 minutes only).

A comparison of few hours to few minutes creates a lot of difference at the time when the world is grappling with a pandemic like COVID-19.

Serological tests detect human antibodies, which are known to be much more stable than viral RNA. Also, these antibodies are typically uniformly distributed in the blood, meaning fewer variations than nasopharyngeal viral RNA. These features provide scalability, meaning serological assays can be used on a wide scale or whole population. However, serological tests also have some limitations, mainly related to the slow pace of the human antibody response to SARS-CoV-2, as antibodies to the coronavirus take several days to develop after the initial infection.

A Well Planned Combination of RT-PCR and Serology Test Should be the Logical Way Forward

It is important to understand that serological tests alone may not be enough to diagnose COVID-19, due to concerns over its accuracy. Rather than seeing RT-PCR and serology as competition, they could be complementary solutions and used in conjunction with each other.

While serology test can be used for initial identifications at a larger scale, RT-PCR can be used on more focused population and as a further validation tool.

This is issued in the public interest. To know more about our research, contact us.