BIOLOGICAL AND HEALTH SCIENCES

The use of a new rapid and inexpensive molecular diagnostic test of COVID-19 was approved

CONICET scientists led this test’s development, which is part of the ‘Coronavirus COVID-19 Unit’ created by the Ministry of Science, Technology and Innovation, CONICET and the agency I+D+i.


Adrián Vojnov and Carolina Carrillo along with Alberto Fernández, Ana Franchi, Roberto Salvarezza and Ginés González García.

The ‘Administración Nacional de Medicamentos Alimento y Tecnología Médica’ (ANMAT) validated the use of NEOKIT-COVID-19, a new COVID-19 diagnostic kit, which is economical and easy to use. By means of a respiratory sample, the test indicates in less than two hours if a person is infected or not with Coronavirus SARS-CoV-2.

The initiative is part of the Coronavirus COVID-19 Unit jointly created by Ministry of Science, Technology and Innovation; CONICET and the National Agency for the Promotion of Research, Development and Innovation (Agencia I+D+i).

The test was developed by CONICET scientists at the Institute of Science and Technology César Milstein (ICT Milstein, CONICET-Fundación Pablo Cassará). It was coordinated by researcher Adrián Vojnov in association with the firm NEOKIT SAS, formed on the basis of one ‘Public-Private Consortium (CAPP) between CONICET and Laboratorio Pablo Cassará S.R.L.

 

Another demonstration of the capacity of Argentine scientists

When it was communicated, the authorities of the area of Science and Technology expressed their satisfaction with this achievement of Argentine science.

“We want to highlight again our pride and recognition for the research work conducted by Dr. Adrián Vojnov at the Instituto de Ciencia y Tecnología Milstein. This new, rapid and safe detection kit of the virus is the result of team work and the commitment given by the scientific community and CONICET for this challenge,” stated Ana Franchi, president of CONICET.

The Minister of Science, Technology and Innovation, Roberto Salvarezza, said: “This is another demonstration of the capacity of our scientists to respond to the needs and urgencies of the Argentines. Almost two months ago we decided to resort to science and technology to face the pandemic in Argentina. Today we have developments that do not only design new strategies to control the disease but also to provide more technological sovereignty to our country.”

 

A rapid and early molecular diagnosis method

Considering the huge amount of information on “rapid tests” given in the last few days and the focus on the speed of a positive or negative response, it I relevant to take into account some aspects of the base technologies of different diagnosis methods.

As well as other respiratory viruses, SARS-CoV-2 can be diagnosed through direct and indirect methods. The former are aimed at detecting the genetic material of the virus in respiratory samples whereas the latter recognize the presence of specific antibodies against this virus (which are part of the immune system’s response to it) in patients’ blood. This goes beyond the time it takes to deliver the results.

“We’d like to emphasize that in addition to being fast (as the results take little time to appear), this test is precocious since it allows the infection to be diagnosed shortly after the viral load entered the body. Serological tests require that the antibodies begin to be produced, which occurs only several days later,” explains Carolina Carolina Carrillo, one of the CONICET researchers who participate in the study at the ICT Milstein.

NEOKIT-COVID-19, like the reverse transcription polymerase chain reaction (RT-PCR) –a testing technique used by the Instituto ANLIS/Malbrán and decentralized centers–, is based on a direct detection molecular technology that from one RNA sample can identify different regions of the SARS-COV-2 genome sequence (which are expressed in RNA sequences).

The technology used in the operation of the new diagnostic kits is known as loop-mediated isothermal amplification (LAMP) and, as well as RT-PCR, it works on the principle of multiplying the number of copies of a certain fragment of DNA or RNA (which in this case is isolated from the respiratory sample extracted from the patient). The great difference is that all the reaction takes place under one same temperature so that a thermocycler is not required.

 

A simple procedure

“The advantage of the kit we developed as regards the RT-PCR technique is that although it has the same sensitivity and earliness to detect the infection, it provides faster results, and the equipment needed is not complex and is much less expensive. It is easy to maneuver and the results are easy to interpret. So it is not necessary to be handled by highly qualified personnel. Besides, the reagents it requires are also cheaper,” Vojnov explains.

The procedure to test with NEOKIT-COVID-19 is simple. The sample of ARN to be analyzed must be placed in one solution in which reagents are mixed with dyes. Then the tube should be closed and incubated at a temperature of 64 degrees for about 60 minutes. When uncovered, if the mixture remains purple, the result is negative; but if it turned blue, the result is positive.

So far, in the same way it occurs with the RT-PCR technique, the test developed by the scientists at the ICT Milstein requires the previous isolation or purification of the genetic material to be analyzed (viral RNA) present in the raw respiratory sample extracted from the patient. Although it is relatively simple and does not take a lot of time, this procedure needs a laboratory with biosafety cabinets, because at the time the sample is taken, the virus is still active, and it requires qualified personnel to conduct it.

“At this moment we are working to find a way to avoid the step of having to purify the RNA by replacing it with a simple treatment of the respiratory sample –in this case, taken through a mouth swab– which ca be done, without risking their health, by a person with some training although the biosafety booths would still be necessary,” says Vojnov.

“We have evidence that this is possible, but first we have to test them in the laboratory and then have it validated by the regulatory entity.”

 

A sensitive and specific test

NEOKIT-COVID-19 offers not only a high degree of sensitivity, which reduces the possibility of having false negatives, but also specificity, which minimizes the probability of false positives.

This is because the test was designed to be able to identify four different regions of the SARS-CoV-2 genome sequence, which are specific to this virus. The task of identifying these regions based on the sequences known for SARS-CoV-2 and at the same time ensuring that they do not cross with those of similar organisms, such as those of other Coronaviruses, was carried out by Santiago Werbajh, researcher of the Foundation Pablo Cassará.

 

The importance of having the support of the State

“It is worth mentioning that this study was conducted thanks to the support of the Ministry of Science, Technology and Innovation and CONICET. For us, researchers, it is fundamental to have the support of one public structure,” Carrillo concludes.

CONICET researchers Luciana Larocca and Fabiana Stolowicz at the ICT-Milstein participated in the study.

By Miguel Faigón