Ahoy! Friendly Neighborhood Scientist here!
Sorry for being silent lately. I have been helping the NM Film Industry sort out their new COVID start-up stuff. We are hoping to follow the rules above and beyond to demonstrate no run-away infections. We have failed if you hear about studio outbreaks in the news. L
Wanted to do a bit of news clean-up for us since it has been a minute.
-- Trust a positive; be wary of a negative.
Positives are actually harder to come by than we thought and there are no false positives at this point. False negatives still happen largely because the person who is positive is being tested via nasal swab after the virus has left the nose or they are not swabbing deep enough or they are swabbing one side of the nose and not the other, and so on. Some of it can be user error and some of it is virus behavior.
-- Virus behavior: it is NOT a respiratory disease, it is circulatory.
It enters the body most easily via air droplets (breath, cough, sneeze, shouting, conversation) – hence the obsession with masks and distancing. One it has entered through the nose, mouth (and sometimes eyes) the easiest connection to the bloodstream is in the lings – hence the appearance of it being a respiratory disease. But once in the bloodstream it and be a bad actor and cause al kinds of fun stuff from blood clots to strokes to other more minor symptoms that can be longer term that are still being learned about.
-- Testing positive one day and then negative the next means you are still positive even without symptoms.
For the reasons above. Depending on when you test, the virus may or may not be detectable in the nose. It is thought that after about 10 days of infection the virus is not as bioavailable in the nasal passages. For instance, if you are tested on day 10 and are positive, but tested the next day on day 11 and are negative – there is a biological explanation for it (and/or swabber error). This is not precise of course because everybody’s body is different and their individual viral load will vary, but you get the idea.
On Convalescent Plasma:
-- We still do not have a good comparative data on the efficacy of convalescent plasma.
Let’s break it all down. First of all, the plasma is being taken from people known to be confirmed cases of COVID. Plasma is the fluid part of your blood separated away from the red, white, and platelet cells. When they spin the blood in a test tube, the heavier cells drop to the bottom and the plasma fluid can be siphoned off the top. Like cream in milk. Plasma carries lots of good stuff including anitbodies throughout the body.
Remember we still haven’t got great information on how long or robust the COVID anitbodies are once someone has been sick, but in a world where we will throw anything at someone dying of this thing, this is another possible treatment. There have been no studies of using the plasma alone without steroid or remdesivir in a dying patient, so it is unclear the true effectiveness of plasma itself. That said, if even there is a perception it works, they will try it, but so far it is indeterminate for its use alone whether it is truly helping.
-- Convalescent plasma is not a cure for COVID.
It is being used in part of the “Hail Mary” kit to save people from dying. That’s it.
Vaccines are hard to make and harder to make sure they are safe. To determine if they are safe and effective, they must test in trials of thousands of people. “Fast tracked” vaccines are likely ineffective at best and dangerous at worst. Not to disrespect the scientists in Russia, because perhaps they do have a useful first vaccine, but they are not allowing anyone to see the data, the process, or the trials (which there haven’t been any that we have seen). It makes the whole thing whiffy, not simply because it is Russian made (I mean, these guys know how to secretly poison people so likely they can make a vaccine!), but because they are not demonstrating any demonstrable science behind it.
That said, once there is a vaccine, take it. I know I said to wait before, but I was hedging that there would be a fast-tracked vaccine that might be pushed forward for political reasons (and I wouldn’t put it past this WH to use taxpayer’s dollars to buy the Russian vaccine before the election and hand it out). However, once we have an approved vaccine, even if it only demonstrates coverage for say three months and one strain (of 7 we know of) – take it – and get a booster three months later.
Why? Because we have not lived with this virus in humans long enough to manufacture a vaccine that will have proven antibody effectiveness and/or long-term coverage yet. It’s only been 8 months! That we are talking about any kind of vaccine right now is nuts compared to the work in the past on good vaccines.
Remember this whole pandemic is a population biology game. The more community spread, the less rule following, the more virus has hosts to hang out in (100% of humans can get it). Being dead is a real possibility, but the concern is spread and allowing the virus to keep hanging out in communities -- and stopping us from going to concerts and stadium sports. If we take a vaccine, even if it’s effectiveness is short term, there are les places for the virus to hang out in us – and fewer of us who can spread it as a result.
Does the virus go away with a vaccine? No, not really. It will always be in the population, but the key is how much of it is there. If it is low and cannot spread and find hosts easily, it will seem to “go away.” But be assured – if you have no vaccine, have not had any contact with it (been tested positive at some point), and it becomes present – 100% chance you can get it even once a vaccine is on board in a lot of the population.
Picture from Truchas NM: She's a doctor too! Love her!