Promising drug treatment for Corona virus (SARS-CoV-2)

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The ever-widening spread of the corona virus is dominating the news. It seems likely that a pandemic is inevitable. The world is in crisis. Yet history has taught us that it is precisely at these moments that humankind comes up with creative solutions, innovations and new insights. This week Innovation Origins takes stock of what innovations in the technical and scientific fields lie in front of us which directly stem from the Corona crisis.

Research is ongoing. But a successful therapy for COVID-19 patients still needs to be found. The healthcare system is currently under enormous pressure due to the lack of treatment options. In particular, the elderly and people with health problems who are more severely affected must be attended to first, as Professor Harald Kessler from the Medical University of Graz (in Austria) explains.


Drugs that have already proved effective against the precursor viruses SARS-CoV and MERS-CoV seem promising. A protease inhibitor in the anti-HIV treatment from the pharmaceutical manufacturer AbbVie has shown some initial success, says Kessler, a laboratory physician. The effectiveness of this drug against the current Corona virus (SARS-CoV-2) is presently being tested in trials.

Since mid-February, the lung infection that broke out in the Chinese city of Wuhan has been called COVID-19, a name which has gained worldwide acceptance. The virus is known as SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) because of its similarity to the precursor SARS-CoV virus.

US pharmaceutical company Gilead is also working on developing drugs to treat SARS-CoV-2 and has already demonstrated the broad-spectrum antiviral efficacy of its drug Remdesivir using animal models. The company is now moving on to phase three of its research and is starting two clinical trials in Asian countries and in countries with high numbers of cases. The primary focus of this study is on the optimal dosage duration for the drug.

Can the infection be recognized quickly?

The infection can be quickly recognized right from the onset of symptoms by using a throat swab to detect viral RNA. The test is performed with the help of a real-time polymerase chain reaction (qPCR). The test result is available within approximately four hours. The epidemic is the first one in recent history that involves quarantine measures.

What is the effect of isolating individuals who have tested positive?

The aim of isolating those infected is to prevent further spread of the infection. By limiting the spread of the infection, we gain some time that can be used to develop specific drugs or a vaccine.

How are patients being treated at the moment?

Patients with mild symptoms only need symptomatic treatment or no treatment at all. For older patients and those who have previously had health problems or suffer from immune system conditions, a more specific therapy would be appropriate. Several basic principles apply here. Current Chinese studies include the use of a protease inhibitor that has already shown its efficacy against SARS-CoV and MERS-CoV. The preliminary successful results also appear to be effective in combating the new SARS-CoV-2. Other medications may also be suitable, such as Remdesivir. But one thing that’s important to mention, is that only mild symptoms have been reported in the cases I am looking at.

How does a protease inhibitor work?

It interrupts the reproduction process of the virus. The protease inhibitor takes up space on the specific site where the enzyme protease binds itself and prevents its effect from manifesting. As a result, the relevant virus components can no longer be produced.

Personal contacts of patients are being looked at. How is this data being used?

Individuals who have been diagnosed with SARS-CoV-2 are either isolated and treated in a hospital or quarantined at home. People who have had contact with them will be screened, informed and, if necessary, may also be quarantined. This is to ensure that no further infections occur and that the chain of infection is broken. As long as the contact person is not showing any symptoms, no tests will be carried out. Only when symptoms are present will SARS-CoV-2 testing be carried out via a throat swab.

Whether the Corona virus (SARS-CoV-2) remains manageable also depends on the speed with which it spreads. Which factors have an influence on that rate – and to what extent can they be contained?

The proliferation rate depends on the basic reproductive value (R0). This is the average number of people that an infected person infects. The higher the value, the greater the chance that a lot of people will become infected and the faster it will spread. In the case of SARS-CoV-2, one infected person infects up to three people. By way of comparison, the R0 value for measles is between 12 and 18.

On the other hand, the rate at which it spreads also depends on the incubation period. Which is two to fourteen days in the case of SARS-CoV-2. Five to six days on average. Therefore, it can take up to 14 days from the onset of infection before symptoms develop. The virus multiplies mainly in the epithelial cells of the lower respiratory tract and leads to associated symptoms such as a dry cough and a sore throat. The incubation time is determined by the infectious dose. In other words,  how much of the virus a person has contracted.

What has the medical profession learned since the Corona virus outbreak (SARS-CoV-2)?

The mortality rate for infections caused by the new virus is currently estimated at up to a maximum of 3%. This is well below the 10% of the SARS epidemic back in 2002 and 2003. Plus the mortality rate for influenza is less than 1%. However, it should be noted that the mortality rate during the pandemic is dropping and is expected to be similar to that of influenza. The reason for this is that cases with just (very) mild or no symptoms are usually only registered retrospectively. It is especially important to note that the mortality rate for SARS-CoV-2 infections is highly age-dependent. While it remains well below 1% up until the age of 50, after that it rises sharply and is close to 15% for people over 80 years of age.

What more does the medical profession need to learn about the Corona virus (SARS-CoV-2)?

There is still a lot to learn if we want to create vaccines and a causal treatment. Existing research projects are not yet sufficiently advanced in their potential applications. For example, analysis of the site where the Corona virus latches onto epithelial cells is of crucial importance for developing a vaccine. This has recently been outlined by American researchers. Yet many more studies are needed. There is also always the possibility that viruses change their genetic make-up. Mutations that alter the characteristics of the virus must be closely monitored.

To what extent can technology support the learning process about the Corona virus (SARS-CoV-2)?

The real-time polymerase chain reaction (NB: a molecular process for the amplification and detection of DNA) is used to detect SARS-CoV-2. It is extremely sensitive and yields a very specific qualitative explanation. At present, it is primarily used for the diagnosis of patients who are critically ill. In a few months time, the detection of specific antibodies of a type of immunoglobulin-G (IgG) with the help of the tried and tested ELISA technology will also be of interest. This will make it possible to determine the actual infection rate.

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