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  • If you're at home social distancing, or sheltering in place like me,

  • you're probably as weary of all the coronavirus news as you are tired of staying indoors.

  • And that's fair. Really.

  • I understand why maybe you'd rather watch a video on ghost particles from Antarctica,

  • or making oxygen on Mars

  • or, for pure escapism, binge watch Tiger King.

  • But I want to explore an important and pressing facet of the COVID-19 coverage: antivirals.

  • Something that you may have heard mentioned in conjunction with developing vaccines to fight COVID-19.

  • We're not a vaccine company. We're a therapeutic company focused on antivirals.”

  • We have to make sure that we've tested all of the antivirals that you have in your collection."

  • "There are a number of antiviral drugs that are being tested.“

  • So, what exactly are antivirals?

  • Simply put: antiviral drugs are medications used to treat viral infections

  • as opposed to bacterial infections, which are treated using antibiotics.

  • Moving beyond this tautology, antivirals inhibit a virus's ability to replicate.

  • This also means they are most effective when administered shortly after infection,

  • before the virus has infected too many of the host's cells.

  • Unlike vaccines, which serve a pre-emptive line of defense

  • by training the body's immune system to fight pathogens,

  • antivirals are by and large administered to people who are already infected with a virus.

  • Another key difference: antivirals are effective only during the time they are being administered.

  • So essentially, antivirals are an effective near-term solution to prevent viral infections from getting worse.

  • But they're no magic bullet.

  • Nearly six decades since the first antiviral drug was approved for use,

  • antivirals have been approved to treat a number of human diseases, including:

  • herpes, chicken pox, HIV/AIDS and Hepatitis B & C—to name a few.

  • Okay. Now that we've got the basics downwhat do antivirals have to do with COVID-19?

  • In January, China shared the genome sequence of SARS-CoV-2,

  • the official name of the virus that causescoronavirus disease 2019,”

  • more commonly known as COVID-19.

  • That's right, as of this video's publish date, researchers have had only three months

  • to study the new virus's genetic sequence.

  • Which means, we are still just learning about this specific coronavirus.

  • Fortunately, researchers can use what we know about other coronaviruses that cause human infections

  • like the MERS virus and the SARS virusto make some educated guesses about SARS-CoV-2.

  • You may recall that coronaviruses have a crown, or corona, of spike proteins that they use

  • to connect with cell receptors on the outside of host cells.

  • Specifically, SARS-CoV-2 uses ACE-2 as a receptor to bind to the host cell.

  • Researchers believe that SARS-CoV-2 follows the same process of replication as other coronaviruses.

  • After binding, the virus fuses with the cell and releases a copy of its RNA genome.

  • Then through assembly, transcription and translation, uses the host cell to make copies of itself.

  • These complete, infectious particles are called virions.

  • Finally, these virions are released to infect adjacent cells.

  • Now, different antiviral drugs are designed to target and inhibit different steps in this process of viral replication.

  • Some target receptors early in the process to stop fusion to the host cell.

  • Others stop replication of the genome.

  • And others disrupt the assembly of new copies, or stop the release of new virions.

  • As of this video's publish date,

  • the total number of confirmed cases of COVID-19 has exceeded 1.5 million worldwide,

  • and that total is projected to continue growing.

  • And with experts saying that it will take more than a year for a vaccine to be ready for the public,

  • researchers around the world are racing for a near-term solution in the form of an effective antiviral treatment.

  • Instead of developing new drugs to treat COVID-19—

  • which would likely take about a decade to reach the publicmany are looking to repurpose antivirals

  • that have already gone through rigorous trial and approval processes to treat other diseases.

  • Two examples: the antimalarial chloroquine,

  • and its derivative hydroxychloroquine, which is also used to treat rheumatoid arthritis.

  • Both have been mentioned repeatedly in the U.S. Coronavirus Task Force briefings.

  • Now, just to be clear, there's currently no definitive evidence that either of these antivirals

  • are effective treatments for COVID-19.

  • Researchers still need to fully evaluate the efficacy of these drugs against COVID-19.

  • But some researchers think these drugs could potentially stop SARS-CoV-2

  • by disrupting binding and interfering with the process of depositing its genome into the host cell

  • stopping the virus early in the process of replication.

  • Chloroquine and hydroxychloroquine also calm immune response,

  • potentially inhibiting a dangerous overreaction from the immune system.

  • Part of what kills people with this virus is the immune response that follows the infection.

  • It ends up causing severe inflammation in the lungs or throughout the whole body, causing multi-organ failure.

  • Dr. Otto Yang and his team are looking at another antiviral that you may have also recently heard of.

  • At UCLA, we have an ongoing study of remdesivir, which is the antiviral drug that's gotten a lot of press.

  • Remdesivir is an experimental antiviral initially developed to treat Ebola,

  • that inhibits viral replication by disrupting RNA transcription.

  • But there's a chance that it might also suppress the immune reaction and inflammatory response

  • that has been a known cause of death for COVID-19.

  • We are setting up trials of things to dampen down that immune response,

  • and see if it can help prevent that damage and reduce mortality.

  • Although it is a double-edged sword because the immune system is there to fight the virus,

  • so you don't want to dampen it and then lose your ability to fight the virus.

  • There's also Favilavir, a drug that's used in Japan and China to treat influenza

  • and is currently being touted asthe first approved coronavirus drug.”

  • Now, it's important to keep in mind that while China has approved it as a treatment for COVID-19,

  • it's hard to even verify what clinical trials were done in China to vet the drug.

  • The reality is there's currently no definitive evidence that any of these antivirals

  • are effective treatments for COVID-19.

  • Which is why, as of this video's publishing,

  • there are no FDA-approved drugs specifically for the treatment of patients with COVID-19.

  • The FDA has approved emergency use of chloroquine and hydroxychloroquine for the treatment of COVID-19.

  • But in the same statement, released on March 28th,

  • the FDA reiterates thatChloroquine phosphate and hydroxychloroquine sulfate

  • are not FDA-approved for treatment of COVID-19.

  • So, it's a little unclear when and how these drugs can be administered.

  • Which may make it difficult for patients to understand what therapies are available to them.

  • The bottom line is, while researchers are excited about repurposing antivirals to fight COVID-19,

  • they need more time to ensure that the drugs work against the novel coronavirus,

  • and to confirm what dosing is most effective and safe for public consumption.

  • So, we're all probably stuck social distancing for a little while longer.

  • That said, this pandemic has motivated and united the medical community

  • to find an effective near-term treatment.

  • And many governments and companies around the world are fast-tracking testing,

  • trials, and approvals to find one.

  • And you can be sure that we'll be all over it when a safe and effective antiviral treatmentor vaccineis found.

  • If you want to learn more about COVID-19, check out our video here.

  • And if there's another aspect of COVID-19 that you want to see us cover, let us know in the comments below.

  • And make sure to subscribe to Seeker for all your viral news.

  • Thanks for watching, and I'll see you next time.

If you're at home social distancing, or sheltering in place like me,

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