Since 31 December 2019 and as of week 2021-2, 94 582 873 cases of COVID-19 (in accordance with the applied case definitions and testing strategies in the affected countries) have been reported, including 2 036 713 deaths.

Viral proteins on the capsid or phospholipid envelope interact with specific receptors on the host cellular surface. This specificity determines the host range (tropism) of a virus.

The process of attachment to a specific receptor can induce conformational changes in viral capsid proteins, or the lipid envelope, that results in the fusion of viral and cellular membranes. Some DNA viruses can also enter the host cell through receptor-mediated endocytosis.

The viral capsid is removed and degraded by viral enzymes or host enzymes releasing the viral genomic nucleic acid.

After the viral genome has been uncoated, transcription or translation of the viral genome is initiated. It is this stage of viral replication that differs greatly between DNA and RNA viruses and viruses with opposite nucleic acid polarity. This process culminates in the de novo synthesis of viral proteins and genome.

After de novo synthesis of viral genome and proteins, which can be post-transrciptionally modified, viral proteins are packaged with newly replicated viral genome into new virions that are ready for release from the host cell. This process can also be referred to as maturation.

There are two methods of viral release: lysis or budding. Lysis results in the death of an infected host cell, these types of viruses are referred to as cytolytic. An example is variola major also known as smallpox. Enveloped viruses, such as influenza A virus, are typically released from the host cell by budding. It is this process that results in the acquisition of the viral phospholipid envelope. These types of virus do not usually kill the infected cell and are termed cytopathic viruses.

29,904 bp positive-sense non-segmented RNA genome

Coronaviruses are enveloped, icosahedral symmetric particles, approximately 80–220 nm in diameter containing a non-segmented, single-strand, positive-sense RNA genome of about 26–32 kb in size

Severe Acute Respiratory Syndrome Related Coronavirus

The spike (S) protein of SARS-CoV2 is cleaved by a cellular enzyme named furin at the S1/S2 site. This cleavage is essential for viral entry to the lung cells. The activated S protein is primed by the TMPRSS2 and finally attaches ACE 2 receptors to enter the host cells. The genetic sequence of SARS-CoV-2 is homologous with the SARS-CoV, and the structure of (S) protein of these viruses is highly similar. They both use the same receptor to enter the host cell; however, SARS-CoV-2 binds ACE 2 receptors with tenfold higher affinity.

Provided good results against SARS-CoV decreased the viral load significantly and provided good results in COVID-19 patients

Lopinavir/ritonavir plus arbidol combination improved significantly the conditions of patients suffering from COVID-19 pneumonia

Inhibits many stages of virus replication: viral entry, transcription, replication, translation, assembly

Commonly used for the treatment of SARS patients suffering from severe pneumonia.

A severe lung condition that causes a low amount of oxygen to go through your bloodstream to your organs (acute respiratory distress syndrome)

If possible, the patients should be treated with mixed inhalation of hydrogen and oxygen (H2/O2: 66.6/33.3%). Patients with severe cases of COVID-19 rapidly progressed to ARDS, causing multiple organ failures and even death. Therefore, respiratory symptoms need to be treated urgently.

And We will surely test you with something of fear and hunger and a loss of wealth and lives and fruits, but give good tidings to the patient, Who, when disaster strikes them, say, "Indeed we belong to Allah, and indeed to Him we will return." Those are the ones upon whom are blessings from their Lord and mercy. And it is those who are the [rightly] guided. [Quran 2:155-57]