Are the COVID Vaccines Unusually Ineffective?

[EPR]

Why do you say that? The Vaccines are highly effective. The data tells us that. In the UK hospital admissions are a quarter of what they were in January and the death rate a tenth.
Vaccines PLUS measures will stop cases not the Vaccine alone. Too many measures have eased off.

Because the R0 is too high and immunity wanes too quickly. There is no way to vaccinate 95% of the world every 4 to 6 months. Some places can for a time... The whole planet- no way.

 

[EPR]

I am not sure who you are supposedly agreeing with. It makes it sound as though you think there will eventually be some more effective vaccines. I think that is extremely unlikely, like science fiction world type of unlikely.

The WHO said this week the virus will become endemic and the world must learn to live with it. This is the experts stance. Vaccines do help. Emphasis on 'help'

 

[bhobba]

Because the R0 is too high and immunity wanes too quickly. There is no way to vaccinate 95% of the world every 4 to 6 months. Some places can for a time... The whole planet- no way.

We do not know once you have had three vaccinations how quickly immunity wanes. You may be right - then again, you may not. Only time will tell.

But there is perhaps a game-changer on the horizon with the Covax-19 vaccine of Professor Petrovsky:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8351577/

When vaccinated stopping further spread will have a dramatic effect on high vaccinated populations. Despite being developed in Australia it got no support and had to go to Iran, where it is now approved as Spikogen. It is seeking approval in Aus:
https://www.clinicaltrialsarena.com/analysis/vaxine-australia-approval-covid-19-vaccine/

Thanks
Bill

 

[artis]

I had the infection this spring, 3 months after made checks had decent antibodies , then checked d6 months after and that decent amount had precisely doubled.
Then I got the single shot Pfizer due to law determined deadlines otherwise I would have kept on the way I was without the vaccine for quite some time as I had no need to apparently as my blood tests showed.
I did complex analysis not just nucleocapsid but also IgA and IgM and whatnot , they all showed I have protection.

Immunity and the level of it is I think a highly individual thing, after all some people die even being fully vaccinated , in my country about 2-5 a day are such.

 

[EPR]

We do not know once you have had three vaccinations how quickly immunity wanes. You may be right - then again, you may not. Only time will tell.

But there is perhaps a game-changer on the horizon with the Covax-19 vaccine of Professor Petrovsky:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8351577/

When vaccinated stopping further spread will have a dramatic effect on high vaccinated populations. Despite being developed in Australia it got no support and had to go to Iran, where it is now approved as Spikogen. It is seeking approval in Aus:
https://www.clinicaltrialsarena.com/analysis/vaxine-australia-approval-covid-19-vaccine/

Thanks
Bill

Then, the vaccination must become compulsory for everyone. The UAE is now very close to 100% vaccinated and it is a nice experiment. Very few cases and almost zero deaths. This, of course, may change once they are stormed by sick tourists, once all measures are removed.
In the mid to short term, vaccination at every 6 months are likely. Or all Hell will break loose.

Antibodies above 500bau/ml are needed for the Delta to effectively remove the possibility of severe disease in most. This can be maintained for 95% of the population via vaccinations every 6 months. The other 5% are more problematic and will keep blocking the hospitals.

 

[Dale]

Because the R0 is too high and immunity wanes too quickly. There is no way to vaccinate 95% of the world every 4 to 6 months. Some places can for a time... The whole planet- no way.

Be careful here. Antibody levels wane. That is not the same as immunity waning. Elevated antibody levels are an acute response to an infection. It is a normal part of the immune response for those to decrease after the exposure ends. The main question, currently unanswered, is if the memory cells can mount an effective long-term immune response.

It is possible that memory cells can mount a strong response long after antibody levels wane and prevent COVID. It is possible that memory cells can mount a strong response, but that the virus moves so fast that a brief COVID infection results. It is possible that memory cells do not mount a sufficient response and that a full COVID infection ensues. Only the last would mean that “antibody-levels wane” = “immunity wanes”

 

[Laroxe]

I think there have been a lot of ideas expressed in this discussion that are not very useful with people comparing these vaccines to others when the comparisons are inappropriate. Covid 19 is caused by an RNA virus, these behave differently to DNA viruses. RNA viruses are less able to correct faults that occur during reproduction, a problem that they compensate for by a much faster rate of reproduction. In fact infection isn't really a numbers game, we appear to need a very small inoculum for infection to become established and once it starts reproducing huge numbers of virions are produced very quickly. This is one of the reasons the incubation period can be very short. Even the flu isn't a useful model, while it's an RNA virus it is very prone to genetic reassortment, this can make it a very difficult target as this causes very significant changes in the virus that alter its immunogenicity.

When infection occurs, a wide range of defences are mobilised, but the response is graded depending on the degree of threat, when infections are symptomatic we often rely on the adaptive responses that take some time to become established. A range of antibodies that are continually refined to improve their effectiveness are produced, and it is often these that remove the infective agent. However, these more elaborate defences are very costly in terms of the resources they use and the increased risks of damage caused by the activation of our immune system. It's worth remembering that many of the adverse events seen after vaccination and after infection are caused by our own immune system. Following recovery, maintaining the high level of readiness is also costly and in most diseases antibody levels start to fall immediately following convalescence. The initial fall tends to be rapid but then slows to a more steady decline, the rate of decline varies with different pathogens and in different people. As Dale points out, interest has now switched from antibody levels to the immune system's adaptive memory systems, while these offer less protection from infection, they do allow for a much more rapid response. As far as I'm aware this type of response continues to offer protection against all the COVID 19 variants with some variations, it seems that the Delta variant has become dominant because of its enhanced reproduction rate.

We can't discuss the vaccines without taking the people into account, infection isn't maintained by simple exposure, it doesn't spread across areas like a wave, it occurs in clusters, often at some distance from each other. It appears that relatively few people are the source of large numbers of infections, it's not quite clear how this works.

Really, the only models that are likely to help are based on the 4 coronaviruses that jumped species in the past and are now considered a cause of the common cold. We only have some limited clues from the last one that appeared in the 1890's, it seems that the world suffered a pandemic of an unfamiliar disease that killed around a million people at the same time. This was eventually labelled the Russian Flu, but there were no tests or even an awareness of a virus. It seems that this virus spread quickly and is still very common, this means that exposure tends to occur when people are very young children and like Covid 19, children appear fairly resistant. This means that all future exposures occur in people that have levels of immunity, the hope is that we will see a similar development with this new virus.

The virus will continue to evolve, but natural selection will likely favour traits that doesn't lead to a disease state that causes people to self-isolate or die. It's thought that the virus's ability to change its antigens is not in any way comparable to the flu but like with the flu it may be that vaccination will only be offered to those most at risk. Current interventions are really ways of minimising the damage caused until this disease becomes a settled part of life, though this can take some time, one way or another most pandemics are self limiting.

 

[artis]

The virus will continue to evolve, but natural selection will likely favour traits that doesn't lead to a disease state that causes people to self-isolate or die. It's thought that the virus's ability to change its antigens is not in any way comparable to the flu but like with the flu it may be that vaccination will only be offered to those most at risk. Current interventions are really ways of minimising the damage caused until this disease becomes a settled part of life, though this can take some time, one way or another most pandemics are self limiting.

I'm just thinking to myself , it can't be that a virus can just keep on making a better more resistant version of itself every next step can it ?
The randomness of mutations would mean that for every win in the lottery the virus would have to lose many many many more times during it's random mutation game. It maybe makes up this losing period by mutating rapidly resembling a gambler on cocaine but it can't "count cards" because that would make evolution not a "blind watchmaker" anymore but instead a skilled and cunning intelligent process.
So now that the delta has swept the world, what are the chances it will make yet another win which would make it win twice in a row?
I feel it should be very unlikely. I am not an expert but it seems to me that the flu for example even though changes every year doesn't become more lethal or more infectious every year.
At least not every year in a row.
The flu is somewhat like "that kid" in class which raises his hand every time and every time he has a different answer but the answer doesn't get better just different.I think it's also interesting to see , probably with time, how our punching efforts will have played out as it seems this is the first major virus that we have had the chance to battle at such a high level given all previous major pandemics happened in a time when we were still pretty much without sharp tools, or any tools for that matter.

But there is one difference, at all other times before the advent of modern travel we were localized and people were not meeting at such a level so we may have better drugs and ways to treat the sick now but we also have better ways to spread the virus, I wonder what the 1918 Spanish flu pandemic would have looked like if it happened today in terms of overall infection percentage and those who died.

 

[Laroxe]

The randomness of mutations would mean that for every win in the lottery the virus would have to lose many many many more times during it's random mutation game. It maybe makes up this losing period by mutating rapidly resembling a gambler on cocaine but it can't "count cards" because that would make evolution not a "blind watchmaker" anymore but instead a skilled and cunning intelligent process.

Well, while mutation is random, it's the process of natural selection that controls whether these mutations become common. Really, only mutations that increase the organisms' fitness will become common in the population. Only part of the evolutionary processes are random.

A virus that causes illness where the person self-isolates, interferes with its own spread and a virus that kills rapidly, kills itself. This is essentially why Ebola has never become pandemic.
Unfortunately, these principles don't always work, and it's not really clear why, it may be that some viruses only evolve very slowly or the period of infectivity is long enough to make these changes irrelevant, there doesn't appear to have been any changes in the lethality of smallpox. It also doesn't apply to animal virus's that can infect humans, but humans are not the principal source of spread. It might also work in reverse, if Ebola evolved to have a longer incubation period and be less lethal, that could be very bad news.

You're right in the observation that the way in which people travel has made the threat much more urgent, air travel in particular means diseases can spread very rapidly. People's behaviour has always been an important consideration in how diseases spread, and many of the ideas have been used for a very long time. Quarantine was established to keep ships carrying infection away from ports, the word refers to the period of 40 days, stopping people spitting was a response to TB, wearing masks, limiting travel and fresh air are all still relevant.

 

[pinball1970]

I'm just thinking to myself , it can't be that a virus can just keep on making a better more resistant version of itself every next step can it ?
The randomness of mutations would mean that for every win in the lottery the virus would have to lose many many many more times during it's random mutation game. It maybe makes up this losing period by mutating rapidly resembling a gambler on cocaine but it can't "count cards" because that would make evolution not a "blind watchmaker" anymore but instead a skilled and cunning intelligent process.
So now that the delta has swept the world, what are the chances it will make yet another win which would make it win twice in a row?

I think it's also interesting to see , probably with time, how our punching efforts will have played out as it seems this is the first major virus that we have had the chance to battle at such a high level given all previous major pandemics happened in a time when we were still pretty much without sharp tools, or any tools for that matter.

The virus is already very good at doing its job, staying viable outside the host and possessing the biochemical machinery that the virus requires from us for it's replication. Mutations 'tinker' they tend not to whole scale shift so this will be drawn out as everyone acquires immunity and we are approaching two years in that process.
Lots of variants that make a brief appearance in the literature may be of interest but then fade off in terms of numbers (Mu may be in that category in the UK)
For the first 12 months we were head and shoulders above the 1918 situation do you think? Genomic analysis, critical care, pathology laboratory analysis, antibiotics, antivirals, ventilators, the general knowledge base and global communications of the scientific community right?
All very true but the bottom line was when CCU started filling up in the UK in April, people with this novel virus were dying at rates that topped cancer and heart disease combined and the healthcare system could do little to stop it. The only thing that did bring the numbers down was lockdown.

We also did not have the added complications from the 17-25 year old spike in 1918, the so-called Cytokein storm that happened in apparently younger healthy people.
Covid 19 does have a lot more of us to aim at in 2021, 7.8 billion people (1918 1.8billion), densely populated cities and global travel all helping the virus spread. Was there an anti vax movement in 1918? (How many Vaccines available!?) Compared to Facebook Scientists of 2021?
Comparisons are limited, I am not an epidemiologist.
The biggest difference between now and 1918 is the Vaccine/s development and roll out.
1918 50M dead (conservative estimate)
2021 5M dead

 

[jim mcnamara]

Vaccination is a point well taken here. Much lower death rate. However, vaccination does not work after a patient has contracted Covid.

US 1918 H1N1 versus SARS-Cov2 --
In discussing this very point - deaths in the pandemic - with an internist who thinks some of the death rate limiting is due to the level of increasing positive medical intervention during the pandemic in the US. She indicated that "phases" of Covid disease progressed and led to deaths very early on. Her hospital had to rent a refrigeration unit because the morgue was overflowing. As treatment modalities improved, patient survival improved. Monoclonal antibody treatment is an example of this kind of change.

She mentioned that NYC Optum data showed for 2nd week of April 2020, very roughly, 10% fatality on any admission of a Covid patient. The last data she saw showed <2% death rate. This only applies to unvaccinated patients.

I do not have access to the data, so I cannot provide any links.

Edit: Optum is a medical group, forgot to mention that.

 

[pinball1970]

Vaccination is a point well taken here. Much lower death rate. However, vaccination does not work after a patient has contracted Covid.

US 1918 H1N1 versus SARS-Cov2 --
In discussing this very point - deaths in the pandemic - with an internist who thinks some of the death rate limiting is due to the level of increasing positive medical intervention during the pandemic in the US. She indicated that "phases" of Covid disease progressed and led to deaths very early on. Her hospital had to rent a refrigeration unit because the morgue was overflowing. As treatment modalities improved, patient survival improved. Monoclonal antibody treatment is an example of this kind of change.

She mentioned that NYC Optum data showed for 2nd week of April 2020, very roughly, 10% fatality on any admission of a Covid patient. The last data she saw showed <2% death rate. This only applies to unvaccinated patients.

I do not have access to the data, so I cannot provide any links.

Edit: Optum is a medical group, forgot to mention that.

Yes I should have noted that over time your chances of getting out of hospital once you were in improved over time between March 2020 and Jan 2021 in the UK. Same elsewhere as care changed.

 

[artis]

There is one major difference though that often gets forgotten. Aslo the reason I think the 1918 Flu was worse than current Covid, back in 1918 there simply were not enough old and sick people around going about meeting others as if their 18 teen and healthy. Back in those days the world especially outside US or western Europe was pretty much a real survival game.

If the knowledge I have from my own relatives and the statistics of my country is of any measure and I do believe they are, then pretty much everyone who has died from Covid either had a serious preexisting condition or was very old, or both. I know of no one personally that would have had a serious case of Covid let alone died under the age of 60. I knew one woman though my former teacher , she had a huge weight problem, she was 49. She contracted Covid recently so the delta variant , had not yet vaccinated and missed the signs at the beginning when she already needed to start treating her symptoms.
Died in ICU after few days from heart failure. She was overweight and had previous heart problems.

I have nothing against old people or sick people but we do have a ever increasing population size in that group which is also largely the group that fills the Covid death statistic.
So I'm kind of willing to bet if we had the population fitness of 1918 and current medical methods/drugs Covid would be far less of a problem. But I will not go there as that would be speculation outside of reasonable prediction abilities.

One thing I can say is that Covid is a weird virus, for those that do develop pneumonia from it the actual suffering comes mostly not from the pneumonia but from the effects of the spike protein.
Given the studies we now have on how it affects CNS and even crosses the blood brain barrier it's a really nasty gift.
I recovered from my Covid pneumonia within a few weeks but the CNS effects continued for couple of months. I guess this is also what causes the so called "long Covid". My blood tests were even fine so physically your fine but mentally you feel like sh**.

 

[artis]

Yes I should have noted that over time your chances of getting out of hospital once you were in improved over time between March 2020 and Jan 2021 in the UK. Same elsewhere as care changed.

And given overall vaccination and new drugs targeting infection I'd say these chances have increased even more now. I'd say you have to be with serious prior illness or in very bad shape to die from Covid now, given you started treatment early and did not do the "ehh I'm fine, I'll ride this one out" routine.

 

[jim mcnamara]

@artis - You need to learn about U-shaped and W-shaped mortality curves. Read the link below
And. Please stop speculating. Post a link to a decent paper please. In other words Biology is often weirder than you would ever dream up on your own. Example: Enzootic pigs are big deal in this whole affair as well.
And H1N1 is still extant after all these years. It is a Type A flu.

The average for deaths in 1918-19 was low, not a U shaped curve. On a population basis, humans in most of the world had not been exposed to the H1N1 virus family since 1887. So relatively younger people died off in droves back then. Data does not back your point about age class distributions back then. There was a mini-epidemic in 1915 of what is thought to be an H1N1 ancestor. See link.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3291398/
Long paper but considered definitive on many aspects of 1918.
Scroll or forward find to heading:
Why Did the 1918 Virus Kill So Many Healthy Young Adults

 

[artis]

Post a link to a decent paper please.

With regards to which statement?

As for the deaths I was only talking about the total deaths not the curves of them. Truth be told Covid is not over yet so only time will tell.
As for age distribution of Covid deaths, I looked at this study
https://www.nature.com/articles/s41598-020-73777-8/figures/2

But I think this statistic is well known and rather similar all around the world by now with few variations from country to country.

PS. @jim mcnamara that paper you linked is interesting , will have a read, with regards to the U or W shaped curves I see how that plays out for the 1918 pandemic but what I said in my post was with regards to Covid and for Covid I'm not sure how to call the mortality curve but it's very low for young kids and young adults and then slowly ramps up until it climbs steeply at around the age of 60 from the graphs I see, so there's that which is why I made the comparison of a healthier younger population having less problems with Covid and our current demographic situation.
But that was just a comment feel free to disregard it, I'm not stating anything.

 

[pinball1970]

With regards to which statement?

As for the deaths I was only talking about the total deaths not the curves of them. Truth be told Covid is not over yet so only time will tell.
As for age distribution of Covid deaths, I looked at this study
https://www.nature.com/articles/s41598-020-73777-8/figures/2

But I think this statistic is well known and rather similar all around the world by now with few variations from country to country.

PS. @jim mcnamara that paper you linked is interesting , will have a read, with regards to the U or W shaped curves I see how that plays out for the 1918 pandemic but what I said in my post was with regards to Covid and for Covid I'm not sure how to call the mortality curve but it's very low for young kids and young adults and then slowly ramps up until it climbs steeply at around the age of 60 from the graphs I see, so there's that which is why I made the comparison of a healthier younger population having less problems with Covid and our current demographic situation.
But that was just a comment feel free to disregard it, I'm not stating anything.

https://www.paho.org/en/news/5-5-20...eople-soar-due-covid-19-paho-director-reports

https://www.cidrap.umn.edu/news-per...-reveal-deadliness-covid-19-even-young-adults

 

[artis]

@pinball1970 That data from the graph I posted was collected I think before the delta variant became the dominant variant so it is entirely possible these graphs will now change with time.

 

[pinball1970]

With regards to which statement?

As for the deaths I was only talking about the total deaths not the curves of them. Truth be told Covid is not over yet so only time will tell.
As for age distribution of Covid deaths, I looked at this study
https://www.nature.com/articles/s41598-020-73777-8/figures/2

But I think this statistic is well known and rather similar all around the world by now with few variations from country to country.

PS. @jim mcnamara that paper you linked is interesting , will have a read, with regards to the U or W shaped curves I see how that plays out for the 1918 pandemic but what I said in my post was with regards to Covid and for Covid I'm not sure how to call the mortality curve but it's very low for young kids and young adults and then slowly ramps up until it climbs steeply at around the age of 60 from the graphs I see, so there's that which is why I made the comparison of a healthier younger population having less problems with Covid and our current demographic situation.
But that was just a comment feel free to disregard it, I'm not stating anything.

Of course an 89 year old has a worse chance of survival than a 30 year old.
I am never sure what point you want to make from this though.
Everyone over 80 we can write off? Over 70? Had their life?
Plus the chances of dying or leaving hospital after Covid with long standing sometimes life changing issues are NOT zero for a young person.

 

[pinball1970]

@pinball1970 That data from the graph I posted was collected I think before the delta variant became the dominant variant so it is entirely possible these graphs will now change with time.

All you need to know is Covid is very dangerous to all age groups just not equally or in the same way.
Re Vaccines
All that is needed to be pinned down is how young the age group they need to go to,how often and what combo (RNA, adenovirus)

 

[Rive]

only mutations that increase the organisms' fitness will become common in the population.

Regarding this, I've come across a really tempting misunderstanding a while ago. Some folks were speculating, that the virus would have only a few possible configuration while converging to some kind of 'optimal' variation, and so once the 'possible' configurations depleted, it would just vanish.

I'm just thinking to myself , it can't be that a virus can just keep on making a better more resistant version of itself every next step can it ?

While it's not entirely impossible to have some kind of 'optimal' variation with a theoretically maximal R0 (! only R0 here) value, the actual effective R depends on the ratio of the already immune people in the population. So when you have the 'optimal' R0 but 70% already immune (by any means), then any 'less optimal' but partially immunity bypassing variant would easily overgrow the 'optimal', regardless of its less potent R0.

In short, that 'fitness' is tricky and really heavily depends on the vaccination/immunity rate. Any 'higher R0' has only a limited and really short lived meaning - don't fall for it.

 

[artis]

Everyone over 80 we can write off? Over 70? Had their life?

No, not at all, that is why I said I don't mean that in a personal way just a statement of statistics.
I am following my local government twitter account and there they report the daily death count and age groups. I don't write the statistics down but I do keep seeing folks in that category with usual age 60+, the next less often one is 40+, very rarely I see anyone under 40 in that group.
Keep in mind my country is about 58% doubly vaccinated overall, so the doors are still open for various outcomes.
One can see in the places where elderly have been almost entirely vaccinated death counts fall, like UK for example I think.
But I guess it's a combination of everything, better tailored drugs, vaccines, safety measures etc that accounts for the global fall of deaths. So we have adapted somewhat is what I see.

 

[jim mcnamara]

I think we are getting into problems with R₀ usage. I have abused it myself mostly because I would have to explain why R₀ obtains only at the start of an epidemic -- if you want to follow the base epidemiology usage. After the susceptible population either dies or becomes immune or vaccinated or whatever, then R₀ no longer has its original meaning and is usually not used. Media reporting excepted, of course.

If you have a R value it will vary depending on how many people a given person interacts with, positivity rates in the population, along with climatic changes, seasonal changes, primary reproduction of the pathogen at the outset of infection (like how many days until the victim can infect new hosts), secondary attack rate (rate of new infections breaking into people in a closed environment -- like worker returning to a house and family) and duration of the outbreak.

Ex: Rancher in Montana versus street vendor in Times Square. There will be a different R values for these populations. This is one reason why it took a longer time for some rural states to reach "critical mass" for Covid to enter logarithmic growth phase in local population there.

Measles has an incredibly high R value - often as high as 10. Epidemics continue as long as the observed R for the population remains above 1.0 Covid in the US as a whole has an R value between 1.0 and ~2.0.

For what it is worth some researchers use
R_t for time changes like April->May
R_s for seasonal -- ex: flu virus does not "like" long days & high solar irradiance (UV)
R_e behavioral and population density like masking/no masking

So you could get an R value for all sorts of conditions if you can work out how to identify them. That means epidemiologists work very hard to develop useful-to-policy-makers-and-general-public R values that can be turned into public health suggestions and policies.

 

[morrobay]

I found this painful to read. The purpose of a vaccine in the very short term (months) is related to anti-bodies. If you are expecting to have benefits longer than a year, antibodies can't be the driver; vaccines need to induce T and B cell immunity as well. Focusing only on antibodies is a horribly inaccurate model.

Adding T and B cells to the mental model is not that hard. I can't understand why people constantly miss this on a science site.

Yes outside of healthy foods and herbs, excercise , healthy weight... I don't know of any natural ways to increase/add T and B cells to the biological model. Following : ' Most of the CD8+T cell responses were specific to viral internal proteins rather than the spike protein'. https://www.cebm.net/covid-19/what-...n-why-immunity-is-about-more-than-antibodies/

 

[Chestermiller]

Is there any indication that Covid vaccine makes Parkinson's symptoms progress more rapidly?

 

[Laroxe]

Regarding this, I've come across a really tempting misunderstanding a while ago. Some folks were speculating, that the virus would have only a few possible configuration while converging to some kind of 'optimal' variation, and so once the 'possible' configurations depleted, it would just vanish.While it's not entirely impossible to have some kind of 'optimal' variation with a theoretically maximal R0 (! only R0 here) value, the actual effective R depends on the ratio of the already immune people in the population. So when you have the 'optimal' R0 but 70% already immune (by any means), then any 'less optimal' but partially immunity bypassing variant would easily overgrow the 'optimal', regardless of its less potent R0.

In short, that 'fitness' is tricky and really heavily depends on the vaccination/immunity rate. Any 'higher R0' has only a limited and really short lived meaning - don't fall for it.

Well like most things the virus will continue to evolve as indeed will its prey. An optimal variation will be in the context of the time and place but if we want to put this in evolutionary terms, its optimal for the virus, the R number and vaccination rate are human concerns though they describe drivers of selection. If you think about fitness for a virus it really is an issue of maintaining its ability to spread and for longer periods. The fact that Covid-19 induces an obvious symptomatic disease that can kill, is not at all in its own interest, people who are ill isolate themselves and limit spread and of course provoked vaccine development and deployment. It is possible that the delta variant was a response to these strategies, but its success can't last, if you look at the other 4 human adapted coronavirus's they have been hugely successful and still are.

 

[artis]

If you think about fitness for a virus it really is an issue of maintaining its ability to spread and for longer periods. The fact that Covid-19 induces an obvious symptomatic disease that can kill, is not at all in its own interest, people who are ill isolate themselves and limit spread and of course provoked vaccine development and deployment.

Well for a virus like Covid , I'd say it has a smart strategy, kill off the weak while maintain spread on the backs of those that are unlikely to die and are also most likely to spread.
So spread through young and healthy and kill old, weak and compromised , given it;s very high transmission rate I'd say if we wouldn't use combating measures I would bet it could go around and around for years until pretty much every weaker individual is gone. It will be interesting to see whether Covid will be able to come up with an even better mutation to increase it's transmission or lethality, I myself would bet that it has already reached it's peak fitness given the delta has now been the dominant variant for quite some time and currently there seem to be no other "better" ones on the horizon.
What I find interesting is that on the random mutation game as I like to call it , having one or more beneficial mutations doesn't increase your chances of coming up with a better or another beneficial mutation, sort of like a gambler doesn't necessarily become better after one or two wins.
In this regard the Spanish flu was much more self limiting as it murdered it's most potent transmission source, namely those that are in their best years of life. 20-40, although pardon if this seems to upset someone, I'm just quoting statistics, on a personal level the "best years of life" might differ from person to person

 

[Laroxe]

Well for a virus like Covid , I'd say it has a smart strategy, kill off the weak while maintain spread on the backs of those that are unlikely to die and are also most likely to spread.
So spread through young and healthy and kill old, weak and compromised , given it;s very high transmission rate I'd say if we wouldn't use combating measures I would bet it could go around and around for years until pretty much every weaker individual is gone. It will be interesting to see whether Covid will be able to come up with an even better mutation to increase it's transmission or lethality, I myself would bet that it has already reached it's peak fitness given the delta has now been the dominant variant for quite some time and currently there seem to be no other "better" ones on the horizon.
What I find interesting is that on the random mutation game as I like to call it , having one or more beneficial mutations doesn't increase your chances of coming up with a better or another beneficial mutation, sort of like a gambler doesn't necessarily become better after one or two wins.
In this regard the Spanish flu was much more self limiting as it murdered it's most potent transmission source, namely those that are in their best years of life. 20-40, although pardon if this seems to upset someone, I'm just quoting statistics, on a personal level the "best years of life" might differ from person to person

My thinking is based on what we know about other coronaviruses that jumped species, though a lot of this is guesswork. It may very well be that every one of these crossover events may have started with an infection that caused serious problems. We know that the Coronavirus OC43 crossed species in the 1890's and its appearance coincided with a pandemic that killed around a million people, this was labelled as Russian flu but they had no way of identifying different viral diseases or even virus's generally. The same virus remains in circulation as the cause of the common cold along with its 3 close relatives from earlier events.
Remember for a virus to kill its host is effectively suicide and people with obvious illness alter their behaviour and the behaviour of people around them in ways which limit spread. Generally, people are exposed to these viruses when they are young, traditionally a period of high risk but for whatever reason they cause few problems but leave the individual with some level of immunity. Most people were not even aware of their existence until Covid-19 appeared.
Flu is not really a very good model because of its particular predisposition to recombine with other flu viruses, this causes massive changes in their genome, significantly altering their immune signatures. However there are some lessons to be learned, like the coronavirus, that pandemic occurred in waves which were of different severity, the first wave occurred primarily in young people and was usually mild. It seemed to spread most readily in the army camps and in army camps with attached field hospitals treating mustard gas victims who were immune compromised and had lung damage. This may have provided the ideal conditions for further viral adaptations as the second wave of disease was more severe and the 3rd worse still. After that the virus started to loose its virulence but the virus family, H1N1 is still in circulation. Its considered some earlier strains of flu may have been sufficiently similar to provide the people exposed with some level of cross immunity, this exposure would have probably been some 30 - 40 years prior to the pandemic but it might help explain its pattern of mortality. The rapid reactivity of young peoples immune response also worked against them with the occurance of the so called cytokine storm, an immune over reaction. Interestingly the virus is now commonly thought to have originated in the USA in military camps and the animals involved in the virus reassortment is still unclear, these are the same issues causing controversy with SARS CoV-2. Remember that a great deal of information about the 1918 pandemic is speculative.
https://www.sciencedirect.com/science/article/pii/S1755436514000346
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6187080/

 

[atyy]

Is there any indication that Covid vaccine makes Parkinson's symptoms progress more rapidly?

https://movementdisorders.onlinelibrary.wiley.com/doi/10.1002/mds.28851
A total of 181 patients with PD met the inclusion criteria; 107 men and 74 women were included. Mean age was 65 years old (range, 31–99). A total of 178 patients received two doses of the SARS-CoV-2 vaccine (177 Pfizer/BioNTech and 1 Sinopharm), and three patients received only one dose of the Pfizer/BioNTech vaccine. A total of 11 patients (6%) had COVID-19 during the pandemic. The effect of the infection on parkinsonian symptoms was not evaluated for this report. Only two patients (1.1%) reported some degree of deterioration following one of the doses of the vaccine. The first patient presented with increased rigidity and gait impairment soon after the first dose that lasted a few days. The second patient presented with increased resting tremor that lasted for 2 weeks also after the first dose. In both cases, symptoms improved spontaneously without any modification of their antiparkinsonian medications.

https://movementdisorders.onlinelibrary.wiley.com/doi/10.1002/mds.28772
In June 2021, the day after her second vaccine dose, she developed fever (38°C), confusion, delusions, and continuous severe dyskinesia for 3 days. Laboratory tests revealed an increased D-dimer level (3228 ng/mL). She was treated with paracetamol, and her levodopa was reduced to 350 mg daily. After 2 weeks, she was afebrile, but mild confusion and dyskinesia that are more severe than her baseline persist.

https://link.springer.com/article/10.1007/s10072-021-05753-7
Conversely, we herein describe a PD patient who benefited from the administration of the mRNA-1273 vaccine. ... The first and second doses of the mRNA-1273 vaccine were respectively administered on May 28 and June 26. Right after the first shot, the patient reported global improvement of his motor and non-motor off symptoms, with greater efficacy on the most affected side (NoMoFA score = 4, 43% improvement; MDS-UPDRS part IV = 7, 30% improvement), and a sustained benefit for almost one week after the second shot.

 

[TeethWhitener]

Is there any indication that Covid vaccine makes Parkinson's symptoms progress more rapidly?

The vaccine doesn't seem to adversely affect Parkinson's patients disproportionately.
https://www.parkinson.org/blog/awareness/COVID-Vaccine-Live-DrOkun
However, persons with Parkinson's who contract COVID-19 are at increased risk of hospitalization and death:
https://www.parkinson.org/understanding-parkinsons/covid-19
There is also speculation that contracting COVID-19 puts patients at higher risk for developing Parkinson's-like symptoms:
https://www.webmd.com/lung/news/20201106/covid-19-linked-to-increased-risk-for-parkinsons