Talked at length with EM doc daughter Saturday–she reports the patient population in her ER ( a hard hit area in CT) has mostly returned to normal. Still getting 2-5 CV-19 patients per day, but are seeing a more normal patient populations–heart attacks, miscarriages, slip-and-fall, strokes, etc–compared to 3 weeks ago.
In case people don’t want to follow the link to the Science Media Center, this scientist’s response is a good overview of the reaction to the Italian doctor’s statements:
Dr Oscar MacLean, of the MRC-University of Glasgow Centre for Virus Research
Other scientists point out that the Covid positive patient population in Italy has become much younger. (I’m speculating that this is because now that the surge is over, there is time and space to see young people with mild illness. Also, tragically, many of the most vulnerable and elderly in areas of high viral circulation have already died.) Younger people may be more able to stop the virus from replicating, and therefore their samples have a lower viral load. Cases are also being diagnosed early now that the system is not overrun. Early on in the disease, the viral load would naturally be lower.
One scientists hypothesizes that “Transmission outdoors is likely to be characterised by lower infectious dose and less severe symptoms, than transmission indoors,” which is interesting, but not proven.
As far as the genetic make-up of the virus, it is being studied extensively and globally. More than 35,000 SARS-CoV-2 genomes have been sequenced and studied. We will know if they find anything definite which could significantly alter the severity of disease.
Lower virulence could increase evolutionary fitness from the virus’ standpoint. For example if a virus spread as easily as SARS-CoV-2 actually does, but infection resulted in no deaths and no post-recovery disability, there would be no human effort to stop it spreading (e.g. social distancing), kill it with treatments, or find a vaccine against it.
I think it’s good news that Eli Lily has begun human trials of their monoclonal antibody for SARS-CoV-2. Other companies are also developing them using different antibodies (which bind to different parts of the virus). The idea is to give these antibodies early on in disease progression to prevent complications, or even right after an exposure just-in-case.
Hoping that none of these engineered antibodies will cause the autoimmune after effects doctors are sometimes seeing in Covid patients.
https://www.cnn.com/2020/06/01/health/eli-lilly-antibody-therapy-human-trial-covid-19/index.html
If SARS-CoV-2 had jumped from bats initially in the less lethal version, with no deaths and no post-recovery disabilities, then it would be more evolutionarily fit because humans wouldn’t have done much to stop it. But all the measures we are taking to deal with the current version of SARS-CoV-2 would equally stop the less lethal version, so it would have no evolutionary advantage as a mutation.
Thanks @BunsenBurner! I think the two have the same chemical structure (when I google one I get the other!)
I have more confidence in therapeutics like this - mostly repurposed antivirals - than in some of the stuff passed off as the latest and greatest.
There are other monoclonal Ab being developed… I don’t see press releases yet so can’t comment.
We will need both immunotherapy and small molecules to hit the sucker with a double punch.
@scout59 - yes, that’s my conclusion as well re: structure.
Heard from a New York intensive care doctor that almost no new COVID-19 patients have severe breathing problems. This is observed in many hospitals. They don’t know the reason.
^Maybe the Italian doctors are right. The virus is not as potent as it used to be 2 months ago.
That would be great news!
One possibility is that, with various anti-virus precautions, those getting infected are getting infected with lower doses of virus, which could lead to less severe sickness.
Well, the virus doesn’t have a brain and lay out some sort of evolutionary plan – mutations just occur randomly and persist if they are successful in the sense of promoting viral spread. And we humans have not yet even come close to succeeding at developing an effective vaccine, much less a coordinated global response. The asymptomatic (or very mildly symptomatic) manifestations of the virus have the best chance of spreading, because asymptomatic people are the ones who are most likely to be out and about working, traveling, socializing, etc. And as horrible as the devastation already has been, there are all sorts of regions in the US & worldwide where it has not yet penetrated in a way that has resulted in much impact. So that leaves plenty of opportunity for viral penetration. If things open in areas and people start to get very sick, then the shut downs will resume – but if things open and a more mild version of the virus takes hold, then people are more likely to ignore the virus and continue with resumed social interaction.
In other words, we are still a very long way from herd immunity and to the extent the virus promotes human behavior that limits its spread, any milder form still does have an evolutionary advantage.
That’s my point, though: the current version of covid already spreads via asymptomatic and pre-symptomatic infection, so the hypothetical new version wouldn’t have much of an advantage there. A person is most infectious before they develop any symptoms they are destined to get.
The mix of those infected has definitely changed, at least in my state. If you look at the WA DOH dashboard, the majority of the new cases are younger folks, those who do not usually require hospitalization. It was quite different in the beginning when the virus hit nursing homes and older individuals. So this is why we likely see fewer hospitalizations.
Emphasizing " They don’t know the reason." If they were younger, they would have said probably because they are younger, not they don’t know why.
What are they admitting the new COVID-19 patients for? At the height of the epidemic, they were admitting for low oxygen. Now what are the symptoms they’re admitting for?
Or maybe because older people (those not in nursing homes/AL which is a congregate setting) are still staying home. Once they start going back out, there will again be more cases and more deadly cases in older populations.
The virus does not choose the people it infects by age. It doesn’t discriminate. It infects whomever is available.
IMO, unless we get a confirmation from the scientistic community, it is for now just a wishful thinking that the virus has mutated so much in these two months that it no longer presents any major health problems and that it will continue to weaken with the same rapid speed. I would be happy to hear such news.
But the behavioral response of humans does change. If 20% of all people infected require hospitalization or significant, often prolonged, medical attention - then the powers that issue orders requiring perfectly healthy people to stay home. I am currently asymptomatic and 99.999% sure that I am uninfected … but I still can’t get a haircut.
If, say, only 5% of everyone infected had those sorts of symptoms – then government restrictions would likely be lifted, humans would start to relax – and healthy me might reward the virus by doing something really crazy, like getting on an airplane to visit one of my family members in a distant city.
With restrictions, the virus can only infect a small fraction of people and then it’s stopped by all the social distancing, mask-wearing, and home-staying. Without those restrictions, the virus is free to infect millions of people. Some of whom, undoubtedly, would still get very ill, but the trick for the virus from the evolutionary standpoint is to get that “very ill” fraction down low enough so that humans will no longer fear the virus and will return to their normal virus-spreading lives.
How would the new less lethal version take over from the old more lethal version? If a less lethal mutation emerged, it wouldn’t be able to take advantage of being able to spread without restrictions. The old version would still be around, so we’d still have to take the same precautions we were planning to take. We wouldn’t get rid of the restrictions.
The less lethal version would take over if it had a favorable environment. But it wouldn’t have a favorable environment. There wouldn’t be any evolutionary pressure favoring new over old.