The COVID-19 unknowns

For the whole 2020 the best minds on Earth have converged on the fight against COVID-19.  Humans learn a lot about COVID-19 quickly.  All the major clinical problems have been understood by early-mid Feb, via scientific publications and media reports by Chinese scientists and doctors and their overseas collaborators.  Important findings include:

1. All the symptoms, including COVID-19’s effects on other organs besides the lung, loss of smell and taste, blood circulation problem, etc.

2. Routes of transmission.

3. Most patients have mild symptoms; only about 20% require hospitalization.

4. Children are less susceptible.  Seniors and those with pre-existing health conditions, such as obesity, diabetes, heart and lung illnesses, are especially in danger.

5. Men have worse outcomes than women.

6. There are the asymptomatic or pre-symptomatic, who may be infectious.

7. Parameters for patient testing, diagnosis, treatments, and discharge.

8. Since late Feb, a small number of patients stay RNA positive for a long time, even though they have been cleared otherwise with no symptoms, and discharged patients might test positive later.  But so far few if any subsequent transmissions have been reported.  

Some of these are more common sense, others are more unique to COVID-19: for example, SARS affected younger adults worse and acted faster and more acutely.  They have formed the basis of all current global medical practices against COVID-19.  Chinese experience also includes how to arrange hospital infrastructures, how to protect medical staff, how to trace cases, how to quarantine or lock down.  Clearly other countries have to decide what to do within their borders.  Public wearing of face masks, more an East Asian practice, has now being adopted more and more in Europe and the US, despite being explicitly discouraged and even warned against until late March 2020.  One has to wonder how it had affected pandemic in these countries.  A strong suspicion, based on common sense rather than actual data, is that masks will reduce not only the chance one gets infected, but also the severity of infection, because if your initial viral load is lower, due to filtering from a mask, your immune system may be more successful fighting off COVID-19.

A glaring failure, though, is a COVID-19 cure has repeatedly come up empty.   In the early days Chinese doctors had tried a multitude of existing drugs and reported success for some under urgent conditions yet loose criteria.   But four months in, none has panned out, except plasma transfusion, which has not been strictly repeated and is not feasible at a large scale.  The “busted” include chloroquine, remdesivir (https://www.marketwatch.com/story/gileads-remdesivir-takes-center-stage-for-now-but-hiv-drugs-make-up-majority-of-sales-2020-04-24?mod=article_inline), Kevzara (https://www.marketwatch.com/story/covid-19-treatment-yields-disappointing-data-in-trial-and-shows-its-not-easy-to-develop-drugs-2020-04-28?siteid=yhoof2&yptr=yahoo), and others.  Although trials are still being conducted in other countries, and some drugs like remdesivir might still be validated in subset of patients, a firm conclusion can be drawn that none of the drugs can be the silver bullet humans hope for, because otherwise the results would have been day and night and leave no doubt of the effectiveness. 

Why don’t we have a cure yet?  A big reason is that the drugs were not developed against COVID-19, so one shouldn’t expect strong specificity, high efficacy, and clean outcomes.  Another reason is that COVID-19 infected so many different people, who have so diverse health conditions and variabilities.  Thus, a drug can help some infections but not others, or induce strong side effects in many patients to exclude its usage.  Miracle HCV drugs by Gilead and others are the exception rather than the norm as far as antivirals are concerned.  HIV/AIDS cocktails work because most infected are younger adults, also because it is a chronic disease.   The last reason is that one can rid a patient of the virus, but if he has other health problems that become fatal, he will still die, even though the drug does its singular job of purging the virus.    

Without a cure, all the doctors and nurses can do is to keep a patient alive long enough so that his or her body can fight off the virus, and his organs can recover later.  A Chinese finding is that the medical staff need to act quick: if one needs intubation, the earlier the better.  As a result, COVID-19 is a test of how strong a country’s medical infrastructure is: how it prevents being overwhelmed, and how it performs under stress.    

 

At this point, the eventual chance for a cure is slim.  Other studies may well find a use for drugs like remdesivir, but likely not under a blanket condition.  In human medical history, with rare exceptions, only antibiotics and vaccines offer universal effectiveness and safety.  Our best hope now is COVID-19 vaccines.  Because the virus doesn’t mutate much, unlike seasonal flu or bird flu, there is a good chance that a vaccine will work, especially when so many people and countries are working feverously on it, from so many different angles.  But until then, the soonest in late 2020 or early 2021, we don’t know, and just have to hunker down.  A potential complication is that if a country develops a vaccine but then has few COVID-19 transmissions, it will be hard to test its usefulness locally.  The vaccine can be tested in other countries, but then it will raise ethical and business issues.