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Tegan Taylor: Hi, this is Coronacast, a daily podcast all about the coronavirus. I’m health reporter Tegan Taylor.
Norman Swan: And I’m Dr. Norman Swan, a physician and reporter, it’s Tuesday, November 10th.
Tegan Taylor: So, since the beginning of this pandemic, Norman, we know animals have been a factor, we’re pretty sure the coronavirus originated in bats, maybe it came via another animal on its way to humans, and there has been a lot of surveillance over the presence of other animals that can catch the coronavirus from us which could then create other places where it could mutate, grow and transmit. And one of these animals that has been identified is the mink, little cute furry animals, and in Denmark it has been seen that there is such a problem that 17 million are being culled. How worried should we be about the coronavirus in mink?
Norman Swan: Enough. Small carnivorous mammals like mink and ferrets are susceptible to SARS-CoV-2, they catch it, and in fact there is a colony of ferrets at Melbourne’s CSIRO where they have tested animal vaccine tests to see if the Vaccines could work because coronavirus behaves in ferrets pretty much like humans, and minks are found to be susceptible to coronavirus too. And I think it was first noticed in the Netherlands and they had a version of the virus called N501Y.
N501Y actually occurred in Australia. There was a cluster of N501Ys in Victoria and now it has become extinct. But actually there was a benefit to this, interestingly, is that they found that it easily infected lab mice, and this turned out to be a great model for testing vaccines in the lab, so there was a nice effect. collateral from this.
Back in the Netherlands, there was evidence of human spread, and there was evidence from people who had taken N501Y, not from mink but had taken it anyway, that when you looked at their convalescent serum afterwards they had not called neutralizing antibodies. to the virus. In other words, their serum wasn’t killing the virus, because this mutation is close to what’s called the spike protein receptor domain, where it gets stuck in our body. So people wondered whether the vaccine would be effective or not because the vaccine is targeted at that part of the peak.
And then in Denmark, the same thing, but a different strain of the virus, this is called N439K, still very common in humans in Europe, again gives very weak neutralizing antibodies in the convalescent serum, and once again worried that may affect the vaccine. All this is unpublished and unverified research.
So the question is, are these two versions of the virus really a vaccine concern? And there’s Australian research, it’s unedited and there’s not much I can talk about for that reason, but there’s Australian research looking at vaccines here that suggests that the vaccine actually produces a much better immune response than the natural infection and could overcome the problems of these variants of the virus. So in other words, if you have a variant of this virus, it will still be affected by the vaccine, it will still be protected, if you want, by the vaccine. At least this is the initial result of the Australian research. So in theory it’s a concern, but in reality it probably isn’t. The real concern is 17 million minks living together by exchanging viruses and maybe throwing away a new one.
Tegan Taylor: Well, when you have the words “mutant” and “animal”, you really hit all the scary buttons and people sat down and noticed. And Lachie sent us into question asking this, saying; With the new coronavirus strain moving from mink to humans, will the measures the Danish government has taken be enough to stop the strain from spreading? And Lachie says; Isn’t it just inevitable that a new strain will emerge that will render future vaccines useless? And it ends with a little crying emoji.
Norman Swan: Well, it turns out that this variety is already in the community, so the mink got away, and I don’t think it came from mink, I think you have to assume it came from humans to mink population. So there isn’t much evidence yet that this is a purely mink variety. It appears this is a SARS-CoV-2 strain that you can see in humans as well as mink.
Could a strain of the virus emerge somewhere that the vaccine does not protect? The answer is yes. And the theory is here that if you fool (to use a professional word) with the vaccine and only immunize a small number of people and do it provisionally, you could give the virus the opportunity to let mutants survive and mutate around the vaccine, not deliberately, but there will be mutants that are actually preserved as vaccine resistant, and you could artificially reinforce those versions of the virus. So the idea here with the vaccine would be to get it known to as many people as possible, as quickly as possible.
Tegan Taylor: So let’s talk a little bit about vaccines, and one of the things we were doing is testing vaccines, and you have to test them on a population that shows you if they work and if they’re safe. And because we don’t know whether they are still safe or not, vulnerable groups are often not included in vaccine trials, including older people, but we do know that older people are the people most at risk of coronavirus and most in need of a vaccine. So why don’t most vaccine manufacturers test them on older people?
Norman Swan: Well that’s a good question, and there’s a study in JAMA Internal Medicine that has shown that indeed when you look at the research that has been done on both treatments and vaccines, given that older people at the age of 65 they are 9% or 10% of the population, but they are 80% of deaths, 40% of cases, you would like to know if the treatments and vaccines work or not. Yet if you look at the studies, a very high percentage, between 20% and 50% could even end up excluding the elderly. And there are so many reasons for this, they may have other diseases.
When testing, drug companies like to have a pure population rather than a real world population. This is a real problem in clinical trials. And actually what the authors argue here is that the exclusions are not well justified and that they should actually test these vaccines on a wide range of communities and as relevant a range as possible in the community. So it is a concern if there has been a significant exclusion of older people from these studies and will limit extrapolation of the efficacy of these drugs and vaccines.
Tegan Taylor: Just to get you on the spot, Norman, do you know if the vaccines that Australia pledged to have a deal with, the four vaccines we talked about a couple of days ago, do you know if any of them have older people included in their tests, because I know the University of Queensland does, but it’s a little further.
Norman Swan: All they have done here is rather than put their finger on particular vaccines that are problematic here, all they have done is list the vaccines that they have reviewed and included the Oxford vaccine and I think in the Moderna vaccine which is the mRNA vaccine. So they actually took a look at those and found that significant numbers have a problem here. So it’s very typical of the pharmaceutical industry, very bad of the pharmaceutical industry. They want to get the perfect result and mess with recruiting and spoil the opportunity for broad generalizability.
Tegan Taylor: And a question here from Peter about Victoria, Peter is saying; Norman, do you really believe all these Victorian zeros, these donut days they say they have? How can they have gone from cases for 150 days to zero, zero, zero? Did they change anything significant in the way they sample, test, or report?
Norman Swan: No, I don’t believe it, I believe it. The way they did it is through blocking, through social distancing, through better testing and contact tracking. The test numbers are right there. The Victorians are doing a great job of coming forward for testing in large numbers. A few weeks ago they were down but now they are up. So everything seems to be right. I haven’t heard any wastewater test reports recently to see if anything is missing. But yes, I believe it, I don’t think there is much missing here.
Tegan Taylor: And one last question from Trevor. The other day we were talking about whether having scotch could kill the coronavirus and we talked about the placebo effect, and maybe maybe it would make you feel better. Well, Trevor is saying; Norman, aside from the placebo effect, would gargle with scotch tape help cure a Covid infection? Would alcohol have killed the virus?
Norman Swan: Thanks Trevor. The answer is that no one really knows. Alcohol in the mouth may kill some of the viruses on the surface but not necessarily below the surface. So you might get a temporary effect. For example, it could neutralize the effect of the tampon, in theory, if you actually get rid of the virus temporarily, but the virus is there and could go out to play after the alcohol is gone.
Tegan Taylor: Yes, and I’d think if you have a nasal swab, you wouldn’t want to snort scotch, no matter how much you like the smell.
Norman Swan: That’s absolutely true.
Tegan Taylor: Well that’s all we have time for Coronacast today.
Norman Swan: Please keep posting your questions, even if it’s still scotch sniffing, and go to abc.net.au/coronacast, click “Ask your question” and mention Coronacast along the way so that we can collect it. See you tomorrow.
Tegan Taylor: See you then.
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