The reason influenza viruses mutate so quickly and occasionally become epidemic is because they are particularly prone to antigenic drift and antigenic shift. CDC: “How the Flu Virus Can Change: ‘Drift’ and ‘Shift’.” Influenza is particularly prone to this because people often get infected with two strains of influenza that recombine into a novel strain, and the occasional transmission to an animal host and then back to human with increased virulence.
We are able to produce seasonal influenza vaccines that target multiple strains of Influenza A and Influenza B viruses with pretty good efficacy (generally better than 70%); when the vaccine is not particularly effective it is generally because immunologists guessed wrong about which strains were most likely to break out rather than the vaccine just not being effective against the targeted strains. Although this isn’t the perfect world of a universal, single-lifetime-dose influenza vaccine, it is close enough to a herd immunity threshold to prevent the flu from becoming a major epidemic even though at best only 30% to 40% of the population even bothers to get immunized. If the SARS-CoV-2 experiences high degrees of antigenetic drift that affects the configuration of the so-called ‘spike protein’ then we might end up needing seasonal vaccines with less than stellar efficacy but again, as long as we have enough of the population immunized it can be prevented from getting to epidemic levels, and the better we understand its mechanisms of action in the more serious presentations we can develop prophylactic and supportive treatments to protect vulnerable people.
Yeah, SARS was squashed so thoroughly that there wasn’t really a need for a vaccine, and MERS is primarily spread from animal-to-human transmission, so while the MERS-CoV virus is found literally dripping from the nostrils of camels, it doesn’t readily spread from person to person. There have been low levels of funding to develop better testing and vaccines for both (which have been leveraged to fight the current SARS-CoV-2 pandemic) but just finding a large enough population to conduct Phase 3 efficacy trials is probably not feasible, so even a developed virus would be of unknown effectiveness.
I’m not really sure what this means. Of course we can’t predict which of the now more than sixty efforts to develop a vaccine will result in a workable product, and even of those that do, how good the efficacy of the vaccine will be, so much research is still needed. It is worth noting that the original Salk vaccine was only about 70% effective, and only about 3/4 of the vulnerable US population was able to receive the vaccine, so the total level of immunization throughout the US population was only ~50%, but this was still enough to stop the waves of polio epidemics rippling through the population nearly overnight. The later Sabin vaccine was far more effective and resulted in virtual eradication of poliomyelitis in the developed world in the 'Sixties.
While the SARS-CoV-2 virus is ‘novel’ in the sense that no human population has evolutionarily adapted to it and few people have developed immunity to it (and we don’t know how long that immunity will last), coronaviruses in general and the SARS-CoV(-1) virus have been extensively studied precisely because because they are a model of how a highly infectious respiratory virus could spread through the population. Nobody can promise when a virus will be available or how close to universal immunity it will provide, but it isn’t a big stretch to predict that some of the efforts will likely come up with a sufficiently effective vaccine to drive the virus down to endemic levels where it can be managed like influenza and other viral pneumoniac viruses like human respiratory syncytial virus (HRSV) which is common in infants and children.
So that’s what you meant? Because what you said was
You’ve made a lot of other “Won’t be a vaccine” pronouncements. You’re sounding like an expert, or maybe just pretty sure of yourself, without providing credentials or evidence.
CarnalK said “isn’t remotely guaranteed,” which is not at all the same thing as “isn’t remotely possible.”
As I interpret it, CarnalK was saying that there’s no guarantee that we’ll have a vaccine, or even close to a guarantee. The probability that we will, whatever that probability is, is not close to 100%. That doesn’t mean that it is close to 0%.
“work on the assumption we won’t get one” is not assuming one won’t be found. “Isn’t remotely guaranteed to happen” doesn’t mean it isn’t remotely possible.
I’ve seen a lot of people say “this won’t be over until a vaccine is found”. That’s crazy.
I just got an email yesterday from my cousin, the virologist, who was on the Ebola vaccine team, and she says that it’s pretty likely a vaccine will be developed (not “found,” “developed”). She is not currently working on one, so she isn’t aware of a timeline, but yes, the previous research on SARS and MERS is giving current research a headstart.
Well, there are no guarantees of anything in life except death (and, they say taxes although certain…individuals seem to have effectively conquered that challenge), and we certainly shouldn’t be staking our entire strategy upon staying inside until a vaccine is available because even when it is (most likely) developed it may not offer an ideal three nines of immunity or may require seasonal tinkering as with the influenza vaccine (although there are reasons to expect that the SARS-CoV-2 virus won’t be as mutable as influenza), but it is certainly reasonable to put significant effort into developing a vaccine because even if we achieve an acceptable level of herd immunity, it won’t make the virus and the disease go away; it’ll just hold it down to endemic levels with periodic outbreaks. We do need to come up with ways of functioning in without a vaccine not only because of the problems posed by this virus but because we will almost certainly face another pandemic like a virulent Influenza Type A strain or another zoonotic virus in the foreseeable future, possibly significantly more virulent than this one, and we need to be able to function as a society and global economy without retreating into our caves every time the specter of pandemic illness rises up.
This is actually, what is pretty significant about this pandemic, and was about the 1918 flu, and HIV as well, was how quickly it whipped around the world. The Black Death pandemic didn’t happen like that, and if international communication had existed (but without international travel, somehow), people might have prepared for it. I mean, really, who knows?
The things is, there were lots of outbreaks of the Black Death during the middle ages, but only one pandemic that was truly global. You read about other things that were described as happening to “the whole world,” but that’s because 6,000 years ago, if it was happening as far as you could walk in a day, it was happening to the “whole world.”
When you think about it, the containment of SARS was pretty remarkable.
But yeah, we need a better way of dealing with the next one.
Some places are now using AI software to help in research , not sure how much of that was done for other diseases . AI found around 70 chemicals that might be good treatments.
Don’t imagine this is anything wildly special. This isn’t artificial intelligence in the way it gets sold to the general populace. AI in these sorts of uses is little more than heuristics to reduce the search space from an impossible number of possibilities to something manageable. It sounds grand and wonderful. But as noted above - it really just means - “we used computer programs to help search for stuff”.
This isn’t to belittle the effort and advances that have occurred in researching and the application of these techniques. It is pretty cool. But there is nothing magically special going on.
There are valid questions about long-term effects of a nasty case of covid - so it’s not just surviving, it’s minimizing the damage.
My WAG on that is that if there is an effective treatment that improve your chances of surviving once you have it, it should reduce the overall damage - but I expect there will still be some. My husband and I were speculating the other day that if either of us got a moderately bad (but survivable) case of it, it would be a career-ender as we might never feel well enough to be able to work again.
So we need to a) have fewer cases AND b) have those cases more survivable with less long-term sequelae.
It is, almost but not quite, impossible to judge long term effects from a four month old disease. Yes, you might be knocked out of the workforce by a moderate bout. Might. I don’t see why you would think it’s particularly likely though.
Morbidity for people hit hard is almost certainly an issue. At the extreme, people who have been on a ventilator for three weeks may take a very long time to fully recover, if ever. Some of the other possible nasty effects similarly. I haven’t heard much more about atypical clotting in patients, but this could also lead to lots of long term damage. A cohort of walking wounded could be with us for quite a while. That is a long term cost that is both hard to estimate and seriously worrying in prospect.
They never have developed a vaccine for it. But they have developed ways of treating it which are not 100% though. They also work with vulnerable populations and use education to reduce methods of transmission.