There is a reason why there haven’t been any human based vaccines for corona viruses. Planning on an effective COVID-19 vaccine without excessive human side-effects being produced in the next five years looks pretty unrealistic. I’m concentrating in this post on giving accessible overviews in the links. But ones that reflect my reading further into the science areas.
There are lot of vaccine projects for COVID-19 underway. Wikipedia has an accessible summary. But there were after SARS as well, without anything that actually went to human trials, even 13 years after the outbreak.
Just looking at the history of trying to get useful vaccines for the SARS or MERS cousins of COVID-19 makes it obvious that getting a vaccine for corona viruses is tricky. Who really wants a vaccine that is more likely to cause lower lung inflammation than the disease itself?
Moreover at present there is no particular reason to expect that any natural immunity from COVID-19 will be persistent over the longer term. Any immunity acquired from either getting the disease or a vaccine is liable to fall away within years, if not mere months.
We never really got to see this with COVID-19’s cousin, SARS. It was so virulent that victims almost all wound up in hospitals, taking them out of infectious circulation. SARS died out in the human host population because it was too obvious. COVID-19 mostly has mild symptoms, and it hasn’t been around for long enough to see if reinfection is possible. But the WHO and medical systems everywhere will be looking for it – like this report from South Korea.
The most accessible overview of medical strategies that I have seen so far was on the aussie ABC site yesterday. “We’ve never made a successful vaccine for a coronavirus before. This is why it’s so difficult“
For those pinning their hopes on a COVID-19 vaccine to return life to normal, an Australian expert in vaccine development has a reality check — it probably won’t happen soon.
The reality is that this particular coronavirus is posing challenges that scientists haven’t dealt with before, according to Ian Frazer from the University of Queensland.
Professor Frazer was involved in the successful development of the vaccine for the human papilloma virus which causes cervical cancer — a vaccine which took years of work to develop.
And while we have vaccines for seasonal influenza, HPV and other diseases, creating a new vaccine isn’t as simple as taking an existing one and swapping the viruses, said Larisa Labzin, an immunologist from the University of Queensland.
“For each virus or different bacterium that causes a disease, we need a different vaccine because the immune response that’s mounted is different,” Dr Labzin told ABC Science.
The basic problem with vaccines for upper respiratory tract infections is that area is an external interface to the air. It effectively has its own immune system, one that has proven to be far more tricky to develop a vaccines for than for viruses that attack via through our circulatory or digestive systems.
“One of the problems with corona vaccines in the past has been that when the immune response does cross over to where the virus-infected cells are it actually increases the pathology rather than reducing it,” Professor Frazer said.
“So that immunisation with SARS corona vaccine caused, in animals, inflammation in the lungs which wouldn’t otherwise have been there if the vaccine hadn’t been given.”
This showed up in both the early SARS vaccines and even the ones that were produced for SARS and MERS within the last 5 years.
Sure, COVID-19 has now produced a very strong incentive for humans to produce a vaccine. And COVID-19 isn’t going to leave the human host population anytime soon, so there will be a continuing incentive.
But you have to be aware of where the corona viruses COVID-19 and SARS and MERS came from. They almost certainly arose in bat populations, transferring to humans via other species, and eventually becoming infectious between humans.
Bats are mainly colony species and not noted for their social distancing where they roost in caves or trees.
To allow this kind of social behaviour, bats also have fierce immune systems. Cell level studies like the one referred in “There’s Something Special About Bat Immunity That Makes Them Ideal Viral Incubators” explain some of the consequences from other species that bats come in contact with.
That’s because one of the molecular mechanisms in bats’ immune systems is the lightning fast production of a signalling molecule called interferon-alpha, which is triggered in the response of viruses. When interferon proteins are secreted by virus-infected cells, nearby cells go into a defensive, antiviral state.
The African green monkey cell line does not possess such advantages. In experiments, when the cell cultures were exposed to viruses mimicking Ebola and Marburg virus, the monkey cells were quickly overwhelmed. The bat cells, on the other hand, resisted the viral onslaught, thanks to their rapid interferon signalling.
The paradox, though, is that interferon ultimately seems to benefit viruses, even while it hinders their capacity to kill cells. While the signalling system prevents cells from dying, the infection nonetheless holds on, and the virus starts to adapt to the defensive regime, at least according to the team’s computer simulations.
“This suggests that having a really robust interferon system would help these viruses persist within the host,” says biologist and first author of the study, Cara Brook.
“When you have a higher immune response, you get these cells that are protected from infection, so the virus can actually ramp up its replication rate without causing damage to its host. But when it spills over into something like a human, we don’t have those same sorts of antiviral mechanism, and we could experience a lot of pathology.”
And that is the key point. We simply haven’t evolved to deal with or live with diseases at this level at a cell or molecular level.
We have no known verifiable treatments apart from just trying to keep severe cases alive with ventilators.
We probably only have one strategy that we know actually works for us. Social distancing.
We also have no idea how much that dealing with COVID-19 depresses our immune systems over the short or long term. What we do know is a bit depressing – we get respiratory co-infections of other diseases with infections of COVID-19.
We also know that the disease is likely to be infecting nerve tissue or even crossing brain-blood barrier. The widely reported symptom of losing small and taste senses clearly points to that. But there are more severe reports of other nervous system related issues. There is an accessible report in Wired “What Does Covid-19 Do to Your Brain?“. That has severe implications because the long-term economic costs of a disease that afflicts nervous systems is quite evident when you look at the 20th century history of polio.
Covid-19 is likely to remain endemic in human populations worldwide for the foreseeable future. That is what we need to plan on, at present, rather than some mythic vaccine or treatment.
We have a choice in New Zealand at present about being able to produce an economy at present that will largely or even (maybe) wholly free of COVID-19 outbreaks. Or to learn to live with the country or parts of it having economy damaging waves of infectious disease outbreaks as was common in the early part of the 20th century with diseases like polio or diphtheria.
The choice requires that we look at the types of businesses and parts of the economy that can be opened in the short-term and over the longer term.
For anyone who can read basic science and knows the history of luck involved in vaccine development, this is pretty obvious. Evidently it isn’t that obvious to many of our local brainless pundits who appear to be more concerned about industries that will be dead while a worldwide pandemic continues over the next decade. Unless a scientific miracle happens and it turns out humans can achieve long-term herd immunity against a sneaky bat disease in the short-term via vaccine or natural immunities.
But if we’re careful, in NZ we can shift the portions of our economy that risk us.
I think that our incoming tourism industry is going to be pretty dead. As will be our outgoing tourism industry. Same for the overseas student industry. Importation of skilled workers will become fraught with uncertainty for quite some time. What employer would want to deliberately take the chance of infecting their other employees? The film industry can probably deal with quarantine weeks. And the cross-tasman business commuters are going to need to decide what side they stay on.
Basically shipping people around the world isn’t going to be a basis for any industry for some time.
But shipping sea and airfreight with some restrictions has no real issues. That is where our real economy lies – both rural and urban.
Most of our outwards facing businesses are already remote capable and have been for years. Rather than hopping on plane and taking 10 or 24 hours to get to where our customers are (I haven’t been to aussie since 1992) we can (mostly) do everything via the net. Some things can’t be done like that. I spent many months in 3 to 6 week chunks doing hands-on work in various countries in the last 4 years. But when you’re doing work at that level, then a few weeks quarantining one or both ends isn’t that much of an imposition – provided you have networks
Certainly every export business that I’ve been involved in has been largely remoteable for at least a decade. 5/6th of our overseas earning income won’t be particularly affected long term.
Our internal economy will have issues until we get down below level three. But then we will mostly it will be a transition away from dead or nearly dead industries over the next 5 years.
Brian Easton has a pretty good overview of the prospects over at Pundit “Where Is The New Zealand Economy Going?“. But he also has a pretty clear warning about what happens to our economy when you have dithering leadership wanting to go back into the comfy blankets of the past.
Fortunately I detect none of that from Labour or the Greens, and only muted echos of it from NZ First and most of the public. The clarity of policy and vision in our government has been awesome to watch. A bit ragged around some of the implementation – but what else did you expect from the on-rushing events. I’m really glad that previous governments kept updating the pandemic response policies over the decades. It paid off big time.
So I’ll end by quoting a large chunk of Brian Easton’s analysis.
However, I do not think that they have paid enough attention to the impending collapse in some of our foreign exchange earners. Together, international tourism and educational services generate about a sixth of our export revenue.
Admittedly there will be some substitution by domestic tourists confined to home, but they wont be at the expensive end – we tend to stay with friends. And there may be other uses – hotels for the homeless. (Would it not be just great if the upper education sector abandoned its commercial pursuits and focused on education?)
A supply-side shock of this magnitude has happened once before. In 1966 the price of wool collapsed, also taking with it about a sixth of our foreign exchange earnings. Policy handled it very badly, ignoring the structural change or pretending that it was of no great significance. As a result, it took a decade to adjust and when we got back to ‘normal’, the long-run track was about 15 percent lower than the previous one.
Let’s be optimistic, assume we handle the impact more intelligently and that the magnitude of the damage is about half that of the wool price crash. (If we assume there will be no long-run impact, we will handle it badly.)
What all this suggests is that we shant be back on track until around 2026 and the economy will be tracking between 5 and 10 percent lower (depending upon the world economy).
That mucks up the Treasury short-term forecasts. Rather than its assumption of a short sharp drop and a rapid recover to somewhere near the pre-Covid19 track by late next year or shortly after, we may well be struggling for another five years at least.
Bugger! I have just made a forecast. Hopefully I am wrong. But it is what years of working on New Zealand’s economic history (see here and eventually here) has taught me. Econometrics and common sense is not enough. A knowledge of the past is as important.
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