Matt Ridley is rationally optimistic that within a month or two, one of the 30 or more therapies for COVID-19 currently being tested is likely to prove effective and safe

Saturday, April 25th, 2020

Matt Ridley is rationally optimistic that within a month or two, one of the 30 or more therapies for COVID-19 currently being tested is likely to prove effective and safe:

The biological problem, as Amesh Adalja of Johns Hopkins University argued in a prescient call to arms just before the pandemic struck, is that viruses do not have their own biochemistry, because they borrow ours.

So unlike, say, tuberculosis, there is not much to attack.


The problem is that viruses differ from each other, so treatments that work for one seldom work for another. The drugs that work against HIV-1, the main cause of Aids, sometimes do not even work against HIV-2,a milder version of the virus. Those that work against herpes don’t kill the very similar cytomegalovirus. One influenza drug works only against influenza A and not B. One antiviral kills just one genotype of hepatitis C. It is no coincidence that the antiviral treatments capable of attacking more kinds of virus, such as ribavirin, are also the most toxic to the patient, because they tend to attack the machinery of the host as well.


Protease inhibitors tend to be highly specific, so the HIV ones are not necessarily useful against Sars-CoV-2. A different protease inhibitor, however, called camostat mesylate, already approved for use in Japan as a treatment for pancreatitis, is showing promise. It was found in 2012 to work against Sars in the laboratory.


In 2015 remdesivir worked against ebola in monkeys, but in the 2018 epidemic in Congo it failed to make sufficient difference to ebola patients compared with other treatments. [...] However, remdesivir is unlikely to be the silver bullet because it is probably best if taken early in the infection, but you would not want to take it if you had a mild bout. It’s administered intravenously and has some nasty side effects.


There is more hope for favipiravir, sold as Avigan, one of the few antiviral treatments showing promise against more than one kind of virus. Bizarrely, it’s made by a subsidiary of Fujifilm, which diversified into chemicals and pharmaceuticals to avoid the fate of Kodak. Invented during the search for a herpes cure, it has since shown promise against influenza. Though good in the laboratory, it was only partially effective against ebola in Guinea in 2014, but initial trials on 80 coronavirus patients in China this year have suggested that it can speed up the recovery time for Covid patients, perhaps cutting it in half. So Fujifilm is now rushing to increase production and the drug has been cleared for use against coronavirus in Japan. The good news is it’s a pill, not an injection, and has few side effects except in pregnant women, where it is not safe.


If chemical treatments do not work, so-called monoclonal antibodies might. If someone recovers, their own body produces antibodies that smother the virus. These days it’s possible to mass-produce exact copies of the antibodies that work, using genetic engineering. Known as monoclonal antibodies, they proved to be the best way to treat ebola patients in Congo in 2018, when the US biotech firm Regeneron came up with a cocktail of human antibodies using genetically engineered mice. Regeneron has rushed a new cocktail of Covid-19 antibodies through the same procedure and hopes to have it ready to test in early summer. Scaling it up for mass production will not, however, be as easy as it would for a chemical pill.


It is not yet clear how [hydroxychloroquine] works: after all, malaria is neither a virus nor a bacterium, but a parasite. But hydroxychloroquine is used against rheumatoid arthritis and the autoimmune disease lupus. In the laboratory, it does seem to slow and inhibit the infection of cells by this coronavirus.

Hydroxychloroquine also tends to team up with the metal zinc and there are persistent and reliable reports that zinc either stops viruses replicating or helps the immune response to them. A gold-standard review of clinical trials found that zinc lozenges do shorten the duration of a cold by somehow interfering with virus replication. This does not just seem to be a diminishing-returns effect whereby having too little zinc, like having too little vitamin D, is bad, but once you have enough, having even more is no better. But if it is, up to a quarter of people in developing countries are deficient in zinc, and zinc deficiency is not uncommon among the elderly in western countries, so this may be part of the explanation why some elderly people are more seriously affected. In short, zinc supplements as a cheap medication, unrewarding to big pharma and therefore neglected, cannot be ruled out as a useful thing to try. Intriguingly, too much zinc kills your sense of taste, as does Covid-19 in many cases.

He has a new book out, by the way — How Innovation Works: And Why It Flourishes in Freedom.


  1. aretae says:

    That’s also been my line for the last couple months. That said,I align pretty closely with the Amazing Mr. Ridley on all sorts of things.

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