Friday, April 3, 2020

What's the latest on COVID-19?

As the evening newscasters are so fond of saying, “this is an evolving story, so stay tuned.” What you hear about the coronavirus seems to change almost daily, and if you are confused, that is because you should be! The traditional way medical research is reported is through publication in a “peer-reviewed” journal. The researchers submit their work and the editors send it to experts in the field for evaluation. These reviewers typically find minor (or major) flaws in the way the study was conducted or how the data are interpreted; their comments go to the researchers, who are expected to rewrite their paper in response. While this does generally result in better science, it is very time-consuming. In the current pandemic environment, many researchers are bypassing the established journal system to post their work on-line, and journal editors are often dramatically shortening the cycle. The good side is that research findings are communicated much more quickly; the bad is that much of what is spread reflects bad science that may not hold up.

That said, I wanted to share what we have learned in recent days, with the caveat that some of this is more conjecture than proof.

The first broad area is how the coronavirus is spread. The CDC believes that some 25% of people infected with the virus are asymptomatic, but still able to spread it to others. A short report published in the British Medical Journal on April 2 from China claims that as many as 78% of new infections detected by culture had no symptoms. Similar findings were reported from a small study in northern Italy. Another new piece of data says that while we are aware the virus is spread by coughing or sneezing, it may also be spread by normal breathing or talking. The bottom line: when you see new advice to wear a mask when out in public, realize that this is more to protect other people from you than to protect you from others.

How about the widely promulgated 6-foot rule? It is based on a Harvard study from the 1930’s. An MIT professor (not Trump’s uncle) claims this is not adequate, and that a vigorous sneeze may propel droplets over 20 feet. Dr. Fauci has no plans to change the CDC advise, but I think we can conclude that 6 feet is the minimum safe distance!

Prevention would be ideal. A vaccine would be best but is a long time away. A peer-reviewed study published this week in EBioMedicine reported on a candidate vaccine that induced an immune response in rodents within two weeks. While encouraging, you must remember that vaccines, which are given to huge numbers of healthy people, must pass stringent tests of both efficacy AND safety before they are approved. Optimistically, we are at least a year away, and probably longer.

A tantalizing study came out this week that showed that the COVID-19 seemed to have less impact in countries that routinely used BCG vaccine, a vaccine to prevent tuberculosis, that is universally given to newborns in Japan and China. It was previously used in France and Spain, but was discontinued years ago, and was never adopted in Italy or the U.S. Several vaccines, including BCG, have been shown to produce non-specific improved immune response against microbes in general. The BCG vaccine is proven safe, and so might be a candidate for use.

Treatment recommendations for established COVID-19 disease rest on tiny studies and are almost certainly going to mislead as much as help.

A study from China looked at the anti-viral agents lopinavir and ritonavir, used for AIDS, and found they had no benefit in a study involving 199 moderately severe patients given the drug combination for two weeks. They are being further studied in larger trials sponsored by the World Health Organization.

How about Vitamin C? If you are a devotee of Internet searches, Linus Pauling’s old miracle cure for colds and many other illnesses will cure COVID-19 as well. Well, Vitamin C does NOT cure the common cold, nor is it likely to cure COVID-19. A trial is being done in China, but do not hold your breath.

Finally, what about the “Trump cure:” hydroxychloroquine (HCQ) with or without azithromax. It makes sense to look at hydroxychloroquine as a possible treatment, as it has been shown to have some anti-viral activity in the test tube, but to date the evidence for its benefit to patients is mixed at best. The early French study which I discussed in a prior post, which claimed 100% clearance of the virus in patients given HCQ and azithromax, was bad science and essentially useless to aid in medical decision-making. Two small clinical trials have shown conflicting results. A Chinese study looked at 62 patients, half given 5 days of 400 mg/day HCQ, and half supportive care, and found that treated patients recovered more quickly than those not given the medicine, and that four of those not given HCQ progressed to severe disease while none of the treated patients did. Sounds good? Unfortunately, another French group studied eleven patients using the HCQ/azithromax regimen and found no benefit, as did a second Chinese study of HCQ. Both drugs can cause serious heart rhythm disorders, and when given together may cause sudden death. The proper role for these drugs, singly or together, is in a proper clinical trial, with careful heart monitoring.

What you should do remains the same as it was last week. Stay away from others. Do not go out if you are sick. Cover your face when out. Wash your hands whenever you touch anything outside (or use hand sanitizer). Wash your hands after dealing with the mail or opening packages.


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1 comment:

  1. Thanks Ed! Very nice, concise and short read. I posted to my FaceBook.

    ReplyDelete