- #36
artis
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@Evo so are you saying you had Covid back in spring 2020, then got vaccinated (double dose Pfizer?) and now got Covid again?
Are the COVID Vaccines Unusually Ineffective?
In summary: The quote concludes that even in highly vaccinated populations there is still a risk of infection. My Summary:From what was said, it's my understanding that a 95% effective vaccine means that for a group of thoroulghly exposed people, 95% of the vaccinated are "immune" and will not get infected or pass the disease along. The protection from infection is all or nothing and whether one can transmit the disease is also all or nothing (the "infected" can, the "not infected" cannot). With COVID, neither the "immune" nor "unprotected" states of the vaccinated are absolute; the vaccines will not prevent people from
- #37
Evo
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Yes. but all very mild. The long Covid, with the neurological problems I described in another thread, I believe, is troubling. There was a woman that died from contracting both Alpha and Delta Covid Simultaneously, you can catch both, I posted the paper on it. Having Covid does not give you immunity, there are papers on that, but I am too incapable of posting them right now. Get Vaccinated if you haven't, it will give you enough immunity to at least prevent infection of a severe and lethal level from the known variants. If you go out, wear masks, social distance.artis said:
- #38
pinball1970
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Yes, I think Alpha came later, Jan 2021? March 2020 would have been the original Wuhan or something close, Before the variants of concern really got going?Astronuc said:
- #39
Astronuc
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Alpha variant, also known as lineage B.1.1.7 was first detected in November 2020 from a sample taken in September in the United Kingdom, and began to spread quickly by mid-December, around the same time as infections surged. But it had been in the UK for some time.pinball1970 said:
I was trying to understand comments: "The Wuhan strain underwent three consecutive mutations, α1, α2, and α3, but these are not found in the closely related CoVs, all of which have the same base at these three positions. The ν variants of the progenitor CoV do not show the other 47 variants at these positions, making them unlikely to be the ancestral lineage for the Wuhan-1 virus or other early samples. The first ν mutant was picked up almost two months after the Wuhan-1 strain.
There were multiple occurrences of the progenitor CoV, both in China and the USA, from January 2020 onwards."
- #40
artis
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Yes @Evo I know how you feel, after my Covid even after the physical defects healed (like lungs) I had a neurological state that was far from optimal for about 2 months. Everything from a irregular heart beat from here to there to dull head from time to time etc ,
I think I was infected with the UK variant which I assume is the alpha in the fancy language, now 3 days ago got a single shot Pfizer.
I already said in another post here that the symptoms after my Pfizer are a bit similar to those from Covid precisely in the neurological case, because I don't have any other symptoms like fever or chills etc.
I think I was infected with the UK variant which I assume is the alpha in the fancy language, now 3 days ago got a single shot Pfizer.
I already said in another post here that the symptoms after my Pfizer are a bit similar to those from Covid precisely in the neurological case, because I don't have any other symptoms like fever or chills etc.
- #41
StatGuy2000
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I wouldn't necessarily use the word "common" to get infected -- more that it is possible to get infected, but be asymptomatic or only mildly symptomatic if someone is vaccinated with any of the main COVID-19 vaccines (as opposed to experiencing potential serious illness if an unvaccinated person gets infected with the SARS-COV2 virus).atyy said:
- #42
StatGuy2000
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As a biostatistician who has been involved in clinical trials for almost 20 years, including in vaccine development (although not on the COVID-19 vaccines specifically), I would like to note that I'm not happy with the title of the thread (that the COVID vaccines are unusually ineffective), as I reject the premise of that title.
Vaccines serve one of two functions: (1) prevent illness among those who are vaccinated, and (2) prevent infection. So let me break this down further.
When the different COVID-19 vaccines have been developed, the main efficacy endpoints in the various clinical trials have always been whether the vaccines prevented illness (which can be ascertained during the Phase III component of the trial by looking at the percentage of those trial participants who received the vaccine ended up developing illness, as well as the level of antibodies developed among trial participants). Based on that criteria, all of the COVID-19 vaccines approved by the FDA (the mRNA vaccines like those from Pfizer and Moderna, the traditional vaccines produced by Johnson & Johnson and Astrazeneca) have all been shown to be highly effective -- up to 95% effective for Pfizer and Moderna, from what I have read in various sources online (will post these sources at a later time). And this effectiveness has been shown to carry over to both the Alpha variant (i.e. the UK variant) and the Delta variant.
The second criteria (preventing infection) is usually something that can only be assessed post-clinical trial in long-term follow-up studies. I have read in various sources that although the current vaccines are not as effective on preventing the spread/infection of the Delta variant as the original SARS-COV2 virus, it is still partially effective. What this means to me is that there is still a potential for those vaccinated to be infected (but most likely not be symptomatic) and hence spread the infection to others (although I have also read reports that fully vaccinated people who get infected tend to clear the virus much more quickly and do not spread the infection as efficiently as unvaccinated or partially vaccinated people).
I have also seen comparisons being made between COVID-19 vaccines and smallpox vaccines to judge the effectiveness, but that is not a meaningful comparison, as effectiveness needs to be judged based on the specific biological characteristics of the viruses involved.
Vaccines serve one of two functions: (1) prevent illness among those who are vaccinated, and (2) prevent infection. So let me break this down further.
When the different COVID-19 vaccines have been developed, the main efficacy endpoints in the various clinical trials have always been whether the vaccines prevented illness (which can be ascertained during the Phase III component of the trial by looking at the percentage of those trial participants who received the vaccine ended up developing illness, as well as the level of antibodies developed among trial participants). Based on that criteria, all of the COVID-19 vaccines approved by the FDA (the mRNA vaccines like those from Pfizer and Moderna, the traditional vaccines produced by Johnson & Johnson and Astrazeneca) have all been shown to be highly effective -- up to 95% effective for Pfizer and Moderna, from what I have read in various sources online (will post these sources at a later time). And this effectiveness has been shown to carry over to both the Alpha variant (i.e. the UK variant) and the Delta variant.
The second criteria (preventing infection) is usually something that can only be assessed post-clinical trial in long-term follow-up studies. I have read in various sources that although the current vaccines are not as effective on preventing the spread/infection of the Delta variant as the original SARS-COV2 virus, it is still partially effective. What this means to me is that there is still a potential for those vaccinated to be infected (but most likely not be symptomatic) and hence spread the infection to others (although I have also read reports that fully vaccinated people who get infected tend to clear the virus much more quickly and do not spread the infection as efficiently as unvaccinated or partially vaccinated people).
I have also seen comparisons being made between COVID-19 vaccines and smallpox vaccines to judge the effectiveness, but that is not a meaningful comparison, as effectiveness needs to be judged based on the specific biological characteristics of the viruses involved.
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- #43
Dale
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Ideally we would have 100% of the population vaccinated and then 100% of cases would be breakthrough cases. There would still be some hospitalizations and some deaths, but the overall risk to the whole population would be substantially reduced.
I was talking with my daughter yesterday about this. The vaccines protect you, but protection is not 100%. Protection is about reducing risk, not eliminating it. Medieval knights wore armor to protect themselves, and it did a good job protecting them. But knights still died, and even some died because of their armor. No form of protection is perfect, not armor, not seatbelts, not condoms, and not vaccines. It is unreasonable to demand that a vaccine must be the only form of protection that is 100% before it is used.
I was talking with my daughter yesterday about this. The vaccines protect you, but protection is not 100%. Protection is about reducing risk, not eliminating it. Medieval knights wore armor to protect themselves, and it did a good job protecting them. But knights still died, and even some died because of their armor. No form of protection is perfect, not armor, not seatbelts, not condoms, and not vaccines. It is unreasonable to demand that a vaccine must be the only form of protection that is 100% before it is used.
- #44
pinball1970
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From the UK in terms of cases, hospital cases and deaths.
Jan to July
Lockdown verses out of lock down
Low vaccination verses level much higher vaccination levels
The weather, older people more susceptible to to respiratory illness.
EDIT : when I post it squashes the peak numbers up- they should be over the two highest values.Cases
peak 68,000 55,000
Deaths
Peak 1800 209
Hospital cases
Peak 4500 1000
Jan to July
Lockdown verses out of lock down
Low vaccination verses level much higher vaccination levels
The weather, older people more susceptible to to respiratory illness.
EDIT : when I post it squashes the peak numbers up- they should be over the two highest values.Cases
peak 68,000 55,000
Peak 1800 209
Hospital cases
Peak 4500 1000
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- #45
artis
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Well it seems that only real graphic that is down is death (which is also good , probably the best of them all) but infection rate is still high. Hospital admission is lower.
about the same where I live
about the same where I live
- #46
pinball1970
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We at a fifth of what we were in terms of hospital admissions and a tenth of the death rate. Just those numbers alone indicate the vaccine has been highly effective.artis said:
Also we have been out of lock down now for about 10 weeks now with schools back.
Cases are high but DELTA is more effective at spreading than ALPHA so relatively speaking the vaccine may well be contributing to keeping cases lower and steady.
It is hard to tease that stat out.The next step is too vaccinate 3 million children, that will take about three weeks if they get going now.
That will have an impact on spread/cases but will not really impact hospital cases or deaths.
Professor Whitty indicated 50% of school children may have already had it but that is counting from last Feb so quite a few kids to go yet.
- #47
bhobba
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I am reading Peter Doherty's book on Covid right now. I think we are discovering that the Covid vaccine is one of those vaccines that work best when given in multiple doses gradually. It was written before Isreal starting giving 3rd doses for all over 12 after five months with excellent results:
https://www.theguardian.com/commentisfree/2021/sep/27/data-israel-covid-booster-shots-standard
As Peter mentions, it can take time for immunity to build.
Thanks
Bill
https://www.theguardian.com/commentisfree/2021/sep/27/data-israel-covid-booster-shots-standard
As Peter mentions, it can take time for immunity to build.
Thanks
Bill
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- #48
Aanta
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As for the OP.
The efficacy of the vaccine is in the same ballpark as for the flu vaccination, in some cases it does not give a lasting protection.
This while these types of vaccine work different than inactivated ones.
Here the RNA will have to enter the cell to make the protein, but RNA is fragile and will deplete.
There's DNA vaccines in testing as this is written, such will give a more long lasting effect.
It is made as a plasmid, which means it will not mess with your other genes.
(Some anti vaxxers claim the current ones are "gene theraphy" which tells how little they understand = nothing whatsoever about what the current COVID vaccines are or what they do.)
Anyway, the plasmid get a translation done with the ribosome and the tRNA then start to make protein in the cytoplasm.
That booster shots are needed also for the 'old' types of vaccines is well known, this is the case both for polio and rabies vaccines for example, and not forgetting the before mentioned flu vaccine - and the latter comparison is the one which is more true now, as flue vaccine have to be repeated as new varieties turn up.
The bottom line is that the COVID vaccine is doing it's job as intended, that it would not give lasting immunity and not be 100% infectionproof was something I knew from the start. Sadly this detail was not brought to everyone's attention by the media.
The efficacy of the vaccine is in the same ballpark as for the flu vaccination, in some cases it does not give a lasting protection.
This while these types of vaccine work different than inactivated ones.
Here the RNA will have to enter the cell to make the protein, but RNA is fragile and will deplete.
There's DNA vaccines in testing as this is written, such will give a more long lasting effect.
It is made as a plasmid, which means it will not mess with your other genes.
(Some anti vaxxers claim the current ones are "gene theraphy" which tells how little they understand = nothing whatsoever about what the current COVID vaccines are or what they do.)
Anyway, the plasmid get a translation done with the ribosome and the tRNA then start to make protein in the cytoplasm.
That booster shots are needed also for the 'old' types of vaccines is well known, this is the case both for polio and rabies vaccines for example, and not forgetting the before mentioned flu vaccine - and the latter comparison is the one which is more true now, as flue vaccine have to be repeated as new varieties turn up.
The bottom line is that the COVID vaccine is doing it's job as intended, that it would not give lasting immunity and not be 100% infectionproof was something I knew from the start. Sadly this detail was not brought to everyone's attention by the media.
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- #49
Dale
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I don't think that is correct. The efficacy of the Pfizer and Moderna vaccines are in the 95% range. Do you have a source that shows the flu vaccines' efficacy levels are in the >90% range. I thought it was lower, but I don't have a number for that so it may be a wrong impression on my partAanta said:
- #50
Aanta
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Hello Dale, I could have made that sentence more clear. Just like the COVID vaccine the flu vaccine might not prevent an infection, but result in milder symptoms. There's several types also, why I used 'ballpark' as there's cell based, attenuated flu vaccine etc. For some types the efficacy is as low as 40 - 60%.
The same numbers also true for some of the alternative COVID vaccine candidates, ones that have not been met with international approval. I knew my reply was long, so it did not include such details as efficacy for vaccines from China, India, or Cuba etc. Astra Zeneca have been given 67-74% depending on study. So to be able to compare and give an answer to the question asked, I picked the best - to simplify.
So I only mentioned the best result for each type, where the general quoted efficacy figure for one vaccine against H1N1 is around 91%.
The same numbers also true for some of the alternative COVID vaccine candidates, ones that have not been met with international approval. I knew my reply was long, so it did not include such details as efficacy for vaccines from China, India, or Cuba etc. Astra Zeneca have been given 67-74% depending on study. So to be able to compare and give an answer to the question asked, I picked the best - to simplify.
So I only mentioned the best result for each type, where the general quoted efficacy figure for one vaccine against H1N1 is around 91%.
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- #51
artis
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Depends on which mutation of Covid we are talking about. For the latest ones on table now that number i believe is lower by 10 or thereabout.Dale said:
- #52
Dale
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Yes, that was more like the range I was thinking of.Aanta said:
- #53
pinball1970
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I thought ≥50% was a minimum?Dale said:
As a requirement?
- #54
Dale
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Yes, 50% was the minimum for a submission for emergency use authorization for COVID. That was not a requirement for other vaccines.pinball1970 said:
- #55
Astronuc
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https://www.burlingtonfreepress.com...te-delta-variant-vaccine-immunity/6367449001/
Children (5-11) have only been approved for vaccination, and 12-18 not too long ago, and the population went back to school and relaxed restrictions.
Children (5-11) have only been approved for vaccination, and 12-18 not too long ago, and the population went back to school and relaxed restrictions.
- #56
EPR
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I agree. The current vaccines are highly unlikely to be the ones that will stop the pandemic.
- #57
Kat-hi
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This only emphasizes the need for therapeutics which should be stressed as highly as the vaccines were. Hopefully the Pfizer and Merck items will help.Astronuc said:
- #58
pinball1970
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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.EPR said:
Vaccines PLUS measures will stop cases not the Vaccine alone. Too many measures have eased off.
- #59
bhobba
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EPR said:
Looks like it. But it certainly will make life close to normal with a few precautions (Pinball is right in some places they have slacked off too much). Here in Aus, we are heading towards 95% over 12 vaccinated (currently 90% first dose and rising - about 95% is the eventual prediction). With the third dose six months after the first two for Pfizer, it is 95% effective. The R0 of Delta is about 7, and 20% of our population is under 12. So let's do some, undoubtedly oversimplified, calculations. That means 75% of our people will be vaccinated with a 95% effective vaccine. They have also discovered with Pfizer, at least initially, you are 50% less likely to reinfect others if you are unlucky enough to get it. I will not take that into account for this simple calculation. The effective reinfection rate R will be 7*(1 - .75*.95) or about 2. Manageable - but measures still need to be taken to control the spread. They likely will not be too onerous - except maybe for those silly enough not to be vaccinated. This will be altered drastically if we vaccinate five and over. 6% are under five, so R then becomes .6. We have herd immunity. But do we have the will to vaccinate those five and over? I ask the question - the answer likely depends on politics outside the scope of this forum.
Thanks
Bill
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- #60
Dale
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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.EPR said:
- #61
EPR
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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.pinball1970 said:
- #62
EPR
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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'Dale said:
- #63
bhobba
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EPR said:
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
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- #64
artis
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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.
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.
- #65
EPR
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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.bhobba said:
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.
- #66
Dale
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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.EPR said:
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”
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- #67
Laroxe
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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.
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.
- #68
artis
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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 ?Laroxe said:
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.
- #69
Laroxe
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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.artis said:
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.
- #70
pinball1970
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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.artis said:
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