The researchers of all the potential therapeutics and vaccines for COVID-19 revealed that they believe the most effective therapeutic drugs will directly target the SARS-CoV-2 virus that causes COVID-19.
Other approaches listed in their review and article published in Antimicrobial Agents and Chemotherapy include blocking SARS-CoV-2 from entering cells, disrupting viral replication, antivirals, vaccines and suppressing overactive immune response.
According to the researchers, SARS-CoV-2 is easily transmissible because Spike (S) proteins on the surface of the virus bind exceptionally efficiently to the angiotensin-converting enzyme 2 (ACE2) on the surfaces of human cells.
One clinical study is already underway, testing if recombinant ACE2 can act as a decoy, binding the S proteins and preventing SARS-CoV-2 infecting cells in patients with severe COVID-19.
The most promising COVID-19 antiviral is remdesivir, which gets incorporated into viral RNA and prevents it being synthesised, halting viral replication.
Remdesivir inhibited SARS-CoV-2 replication in laboratory studies and was tested in one patient with COVID-19 in US.
The patient’s symptoms improved following intravenous remdesivir administration; however, more clinical data is required before the drug can be approved for use.
Tilarone is a broad-spectrum antiviral that may also be active against SARS-CoV-2.
The synthetic small molecule is used in some countries, including Russia and neighbours, to treat several viruses, including acute respiratory viral infection, influenza and hepatitis.
Other studies suggest tilarone may be active against Middle Eastern Respiratory Syndrome (MERS-CoV); however, the studies do not meet US Food and Drug Administration (FDA) standards for safety.
A further treatment option currently being explored, according to the authors, is the transfusion of blood from a recovered COVID-19 patient into someone with an active viral infection.
This has primarily been used for patients in critical condition as it has a lack of high quality randomised clinical trial data to back up its efficacy.
Several clinical trials investigating its effectiveness and safety against COVID-19 are now in progress.
The review cited more than 15 vaccine candidates being developed globally, with various approaches to their design.
The researchers suggest the expert opinion is that it will take approximately 12 to 18 months to get one to market.