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Vaccine Hope

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    Posted: July 15 2020 at 1:17pm

First data for Moderna Covid-19 vaccine show it spurs an immune response

By Matthew Herper and Damian Garde July 14, 2020 

Moderna’s Covid-19 vaccine led patients to produce antibodies that can neutralize the novel coronavirus that causes the disease, though it caused minor side effects in many patients, according to the first published data from an early-stage trial of the experimental shot.

The results were published Tuesday in the New England Journal of Medicine. Moderna had previously released some results in a press release, but many experts said they were not sufficient to draw many conclusions. Even now, many are withholding judgment.

“It certainly is a good beginning,” said Betty Diamond, director at the Feinstein Institutes for Medical Research, who was not involved in the trial. “There are certainly lots of things we don’t know yet right now.”

The study, which was run by the National Institutes of Health, showed that volunteers who received the vaccine made more neutralizing antibodies than have been seen in most patients who have recovered from Covid-19. But a second injection, four weeks after the first, was required before the vaccine produced a dramatic immune response. 

“The hallmark of a vaccine is one that can actually mimic natural infection and induce the kind of response that you would get with natural infection. And it looks like, at least in this limited, small number of individuals, that is exactly what’s happening,” said Anthony Fauci, director of the National Institute for Allergy and Infectious Diseases, the NIH branch that conducted the trial. “The data really look quite good,” he added. “There were no serious adverse events.” 

The data roughly mirror the results from a similar vaccine being produced by Pfizer and BioNTech, which were released July 1.

Moderna posted a listing on clinicaltrials.gov, a government registry, that says it will start a Phase 3 study in 30,000 patients on July 27. Pfizer and BioNTech said they plan to start their own large study by the end of the month. There are 23 vaccines in human clinical trials against the virus, SARS-CoV-2, according to the World Health Organization, with more set to begin testing soon.

In a statement, Moderna CEO Stéphane Bancel called the data “encouraging,” saying they “represent an important step forward” in the development of the vaccine, called mRNA-1273. “We are committed to advancing the clinical development of mRNA-1273 as quickly and safely as possible while investing to scale up manufacturing so that we can help address this global health emergency,” Bancel said.

One big question is whether producing antibodies predicts protection against infection — and how much protection. Another is whether the antibodies will last.

“We don’t know how much [antibody] we need to be protected, so we can’t say” all the participants “achieved a protective level,” Kathryn Edwards, scientific director of the Vanderbilt Vaccine Research Program, said in an email to STAT. “What we can say is that they made antibody that neutralized the virus, which is good.”

The study enrolled 45 healthy volunteers ages 18 to 55, testing three dose levels of Moderna’s vaccine. The trial participants were split roughly 50-50 between men and women. The population was 89% white, 13% Hispanic, 4% Black, 2% Asian, and 2% Native American. More results are expected to be reported later for older patients, who often mount a weaker immune response.

Volunteers got a shot in the arm on day 1 followed by a booster shot four weeks later. At the 100-microgram dose, the one Moderna is advancing into larger trials, all 15 patients experienced side effects, including fatigue, chills, headache, muscle pain, and pain at the site of injection. All side effects were considered mild or moderate.

A higher, 250-microgram dose led to more serious reactions and has been set aside. Although no side effects were severe — meaning that they required hospitalization — they were unpleasant, as was made clear when one volunteer in the study, Ian Haydon, went public with his experience taking the 250-microgram dose.

Researchers and drug companies have been racing with unprecedented speed to create a vaccine against the coronavirus. Moderna began its Phase 1 trial just 66 days after scientists first decoded the genome of SARS-CoV-2.

“It’s amazing just how fast we’ve gotten to this point,” Penny Heaton, CEO of the Bill and Melinda Gates Research Institute in Cambridge, Mass., said in an interview. “It’s like six years of work has been compressed into six months.”

That very speed is a reason for caution, said Paul Offit, chief of the division of infectious diseases at the Children’s Hospital of Philadelphia. He advised companies to be humble. He noted that he had worked on rotavirus vaccines for 25 years, and still the first attempt at one turned out to have a side effect that sent researchers back to the drawing board.

Already, he said, SARS-CoV-2 has done things experts never would have expected, he said. It spreads in hot weather. It causes deadly blood clots. It rarely makes children sick, but sometimes causes a surprising immune disorder. “I can promise you that over the next two years, we’ll learn a lot of things that we wish we’d known now that we are going to learn as we move forward,” Offit said.

Researchers measured the efficacy of Moderna’s vaccine in multiple ways, all of which showed higher average antibody levels than were seen in patients who had recovered from Covid-19. It took time for antibody levels to rise. Only after the booster shot did volunteers compare favorably with recovered patients.

In an editorial in NEJM, Heaton noted that it needs to be confirmed that measurements of such antibodies predict efficacy. “They are the best tools available,” she wrote, “and are supported by findings in nonhuman primates.”

At the 100-microgram dose, patients had neutralizing antibody levels, measured in what are called geometric mean titers, of 231.8 at day 57, compared to 109.2 in patients who recovered from Covid-19.

Experts said that given the multiple types of tests, it is impossible to compare vaccines based on laboratory results between different vaccines. For its vaccine, Pfizer had said that neutralizing antibody levels were 267 at 28 days, but they were 94 (a lower level than Moderna reported) in recovered patients, apparently using a different test. Pfizer has not disclosed data beyond 28 days.

Asked to compare the Moderna and Pfizer vaccine data, Fauci said, “I don’t think you could say anything about one being better than the other. They both induce good responses. Let’s see what happens in the real world.”

Several researchers said that seeing the results increased their hope not so much in Moderna’s vaccine, but in arriving at one or more vaccines that will help reduce the impact of the virus.

“I am cautiously optimistic, based on the data that we’ve seen so far, that amongst the several different vaccine platforms that are being tested, there seem to be encouraging Phase 1 data to suggest that at least one of them is going to work,” said Francis Collins, director of the National Institutes of Health. “And maybe several of them.”

But he warned that such science is not predictable. “Hence the word cautiously is attached to the word optimistic in this situation,” Collins said.


Source:   https://www.statnews.com/2020/07/14/moderna-covid19-vaccine-first-data-show-spurs-immune-response/?utm_source=Nature+Briefing&utm_campaign=8a93e2b69c-briefing-dy-20200715&utm_medium=email&utm_term=0_c9dfd39373-8a93e2b69c-43962649

Related: https://www.statnews.com/feature/coronavirus/drugs-vaccines-tracker/

Related: https://www.statnews.com/2020/07/01/covid-19-vaccine-from-pfizer-and-biontech-shows-positive-results/

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Post Options Post Options   Thanks (1) Thanks(1)   Quote Tabitha111 Quote  Post ReplyReply Direct Link To This Post Posted: July 15 2020 at 2:29pm


Virology Fact of The Day

"Remember to keep your expectations for Moderna’s vaccine tempered.

Although they have finally published some protection data in a preprint, we still need to see more serious data from animal models before we should celebrate.

We know that in the context of SARS-CoV-2, an apparently strong immune response measured without an actual challenge infection (that is, deliberately infecting a vaccinated animal and seeing what happens) doesn’t always mean that the animal will be similarly protected from disease.

We also know that a lack of a strong immune response (by certain measures) to the vaccine doesn’t always mean that the vaccine will not protect from disease. We really need much more data."

'A man who does not think and plan long ahead will find trouble right at his door.'
--Confucius

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Post Options Post Options   Thanks (0) Thanks(0)   Quote EdwinSm, Quote  Post ReplyReply Direct Link To This Post Posted: July 15 2020 at 10:42pm

While good news, I remember reading that there were some concerning side effects.  As only 25 people were in the first stage testing we will need to see more data about side effects and how long any protection lasts.   

One report said that the full data from the larger trial will not be in until 2022, but I expect if initial data from larger scale test is good then there will be incredible political pressure to rush it into use.  

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Post Options Post Options   Thanks (0) Thanks(0)   Quote carbon20 Quote  Post ReplyReply Direct Link To This Post Posted: July 16 2020 at 1:35am

If the immune response is diminished after you've had the WU

What's the hope that a vaccine immune  response will last ??

Am I correct in saying that if you had measles as a child you have immunity for life, but a measles vaccine only lasts a few years...... 

Tetanus shot only lasts 10 years....


Everything we hear is an opinion, not a fact. Everything we see is a perspective, not the truth.🖖

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Post Options Post Options   Thanks (0) Thanks(0)   Quote carbon20 Quote  Post ReplyReply Direct Link To This Post Posted: July 16 2020 at 1:58am

In answer to my own Q.

Just found this


ABC News: Coronavirus immunity: Any antibodies we develop to COVID-19 seem to drop off within months. So what does this mean for a vaccine?.

https://www.abc.net.au/news/2020-07-16/how-long-does-our-immunity-to-coronavirus-last/12460724

Everything we hear is an opinion, not a fact. Everything we see is a perspective, not the truth.🖖

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Post Options Post Options   Thanks (0) Thanks(0)   Quote EdwinSm, Quote  Post ReplyReply Direct Link To This Post Posted: July 16 2020 at 2:07am

Even if the vaccine's effect  is short lived, there are places, like hospitals and care homes, where vaccinating the staff at the beginning of a local outbreak could be valuable.  So I am hoping that even if it does give limited coverage it might still be of use in help keeping the R-figures down.

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Technophobe Quote  Post ReplyReply Direct Link To This Post Posted: July 16 2020 at 3:24am

Flu vaccine is every year.  Once every 6 months would be possible.  Perhaps "vaccination clinics" could open up and keep a rolling process going.

One more category of jobs to "boost the economy".

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Post Options Post Options   Thanks (0) Thanks(0)   Quote WitchMisspelled Quote  Post ReplyReply Direct Link To This Post Posted: July 16 2020 at 4:01am

No need to set up vaccination clinics in the U.S.  That infrastructure is already in place.  Pharmacists,  are permitted to administer vaccines.  I generally get my flu vax at the pharmacy annually.  

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Post Options Post Options   Thanks (0) Thanks(0)   Quote carbon20 Quote  Post ReplyReply Direct Link To This Post Posted: July 16 2020 at 4:19am

Same here WitchMisspelled


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Post Options Post Options   Thanks (0) Thanks(0)   Quote Technophobe Quote  Post ReplyReply Direct Link To This Post Posted: July 22 2020 at 11:12am
                                                

Coronavirus vaccines leap through safety trials — but which will work is anybody’s guess

Scientists caution against comparing immune responses shown in early-stage trials, and say there might be more than one path to an effective vaccine. 

When it rains, it pours. In the past few days, scientists working at feverish pace to develop vaccines against the coronavirus have released a flood of data from their first human trials.

The results come from phase I and II trials of four promising vaccine candidates and detail how people respond to the jabs. Because the trials were focused on safety and dosing, the data cannot say whether the vaccines will prevent disease or infection — large-scale efficacy trials are needed for this. But they suggest that the candidate vaccines are broadly safe, and offer the first hints that vaccines can summon an immune response that resembles that of people who have been infected with the virus. Crucially, researchers say the data look good enough to merit testing the vaccines in efficacy trials, in which volunteers receive a vaccine or placebo and rates of COVID-19 disease are compared between groups.

“I’m really happy that there are quite diverse vaccine strategies going beyond phase I trials,” says Shane Crotty, a vaccine immunologist at La Jolla Institute for Immunology in California.

But scientists caution against over-interpreting the results, and say the data shouldn’t be used to directly compare the different vaccines. Ultimately such comparisons will be vital for identifying how different vaccines work, or why they fail, and to use this information to prioritize other vaccines at early stages and to develop new ones. But researchers don’t yet know the precise nature of the immune responses that protects against COVID-19 — and there are likely to be multiple ways to fend off infection. And measurements of different immune markers made in one lab are difficult to compare with those performed by another team, say scientists.

“The data are so early and so preliminary, one thing to avoid is saying one is better at this stage because we just don’t know,” says Rafi Ahmed, an immunologist at Emory University in Atlanta, Georgia.

Viral vectors

All four vaccine-makers said that their vaccines elicited some kind of immune response in people, broadly similar to that seen in recovered patients. Trial participants experienced side effects common to other vaccines, such as muscle pain, fevers and headaches, but few participants developed serious reactions to the different vaccines. “Most of them are looking quite safe,” says Crotty.

Two teams — at the University of Oxford, UK, in collaboration with AstraZeneca, and researchers at Cansino Biologics in Tianjin, China — that are developing ‘viral vector’ vaccines published1,2 their results in The Lancet on 20 July.

“The vaccine is inducing the kind of immune responses that we think are inducing protection against coronavirus,” said Sarah Gilbert, an Oxford vaccinologist leading that effort, in a 20 July press briefing announcing their results. Oxford’s vaccine harnesses a genetically modified chimpanzee cold-causing adenovirus that expresses the coronavirus spike protein, which the virus uses to infect human cells. Cansino’s, meanwhile, is comprised of a modified human adenovirus.

Another group, BioNTech in Mainz, Germany, which is developing an RNA-based vaccine drug company with Pfizer, released detailed immune data from people who received a vaccine that contains RNA instructions for the ‘receptor binding domain’ portion of the spike protein3. This followed long-awaited clinical-trial results on 14 July4 from Moderna, a biotech company in Cambridge, Massachusetts, that has developed a competing RNA vaccine made of the entire spike protein, in collaboration with the US National Institute of Allergy and Infectious Disease (NIAID) in Bethesda, Maryland. Some details of the results were announced in a press release in May.

Immune response

The latest data offer the best insight yet on the nature of the immune responses prompted by the vaccine — the only indication, short of an efficacy trial, that they are likely to work.

Vaccines work by exposing the immune systems to components of a virus — the coronavirus spike protein, in the case of nearly all COVID-19 vaccines — in hopes of provoking a reaction against a real infection in the future. The trials looked at two broad types of immune response: antibody molecules made by the body that can recognize and, in some cases, inactivate viral particles; and T-cells that can kill infected cells as well as promote other immune responses including antibody production.

So far, most focus has been on ‘neutralizing antibodies’ circulating in the blood, which can render viral particles uninfectious. “All of these [vaccines] are inducing some antibodies that neutralize, which is better than no neutralizing,” says Ahmed. That’s a decent sign, he says. Most vaccine volunteers produced levels of these potent antibodies that were similar to those made by recovered Covid-19 patients, which can vary widely.

But many of the vaccines might require more than one dose to get this response. “I think two doses will be required for many of these vaccines in order to achieve adequate virus neutralizing antibodies,” says Peter Hotez, a vaccine scientist at the Baylor College of Medicine in Houston, Texas.

T-cell focus

T-cell responses have received less attention from vaccine developers. That’s in part because they are more difficult to measure, especially as the numbers of trial participants pushes into the thousands. But emerging data from natural infections suggest that T cells might have an important role in controlling the coronavirus, says Crotty.

The slew of vaccine trials detected varying degrees of T-cell responses in participants. Crotty’s team detected spike-recognizing CD4 T cells, which support antibody production, in all 10 of the recovered patients they examined. Seventy per cent also had CD8 T cells, which kill virus-infected cells, against spike5.

If a vaccine can elicit a combination of neutralizing antibodies and both kinds of T-cells, it could bode well for protecting against disease, says Crotty. But that’s mostly a hunch. “We don’t know the rules for what’s most important for protective immunity,” he says. “It’s definitely plausible that there’s more than one way to protect against this virus.”

The nature of the immune response that protects — or fails to protect — against COVID-19 will become clearer when efficacy trials deliver their first results. “As soon as someone gets efficacy, we’ll have a better idea of what a vaccine needs to do,” Gilbert said in the briefing. Oxford’s vaccine is being tested for efficacy in the United Kingdom, Brazil and South Africa, and the Moderna-NIAID vaccine is set to begin its phase III trial in the United States this month.

Compare and contrast

Such data — known as a correlate of protection — could make it easier to interpret early-stage trial results like those released in this week. But such comparisons are also thwarted by the fickle nature of the tests researchers use to measure neutralizing antibody and T-cell responses. The same test can return widely different values when performed in different labs or even on different days of the week.

“It’s hard for us to compare our vaccine results to other people’s,” Adrian Hill, an Oxford vaccinologist, said in the briefing. “We would really like to see different vaccines being tested in the same lab by the same people.” The US government’s effort to support COVID-19 vaccines, known as Project Warp Speed, is supposed to be making such comparisons, notes Hotez. The World Health Organization in Geneva and the Coalition for Epidemic Preparedness in Oslo, which has provided financial support to nine vaccine developers, have also announced plans to support this work.

It is vitally important to be able to identify immune correlates of protection and to be able to compare vaccines, says Daniel Altmann, an immunologist at Imperial College London. “The stakes have never been higher,” he says. "We so desperately need it."

Altmann thinks that most of the frontrunner vaccines “could do the trick”, but he worries that there is not enough emphasis on identifying vaccine candidates whose developers are most capable of manufacturing and delivering enough vaccine for much of the world. That could depend on myriad issues from sourcing glass vials to maintaining cold chains. “That’s like organizing a Moon landing or a world war invasion. Whichever candidates we pick, we want them to be the ones that can most optimize that.”

                                                        

doi: 10.1038/d41586-020-02174-y


Source : "Nature"  

Source link and refrences:   https://www.nature.com/articles/d41586-020-02174-y?utm_source=Nature+Briefing&utm_campaign=231ffb80b9-briefing-dy-20200722&utm_medium=email&utm_term=0_c9dfd39373-231ffb80b9-43962649

           
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Post Options Post Options   Thanks (0) Thanks(0)   Quote WitchMisspelled Quote  Post ReplyReply Direct Link To This Post Posted: July 22 2020 at 1:38pm

Thanks Technophobe.  Good article to read.

In other news the U.S. has committed to buy 100 million doses of vaccine from Pfizer.  Two months ago they committed to buy 300 million doses from AstraZenica.  All with no viable vaccine yet.  Not sure what to think of this.  

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Tabitha111 Quote  Post ReplyReply Direct Link To This Post Posted: July 22 2020 at 2:32pm


https://www.npr.org/sections/coronavirus-live-updates/2020/07/22/894184607/u-s-to-get-100-million-doses-of-pfizer-coronavirus-vaccine-in-1-95-billion-deal

What’s even better than a fast, cheap, kinda-sorta accurate COVID-19 test? A free COVID-19 vaccine! The federal government has reached a $1.95 billion deal with Pfizer to acquire 100 million doses of its vaccine candidate against the coronavirus if the Food and Drug Administration OKs it. The vaccine would be free to Americans, though health care providers could charge to administer it.

(I am sure they would have plenty of free clinics administering this...health dept, drive up vax lines, etc. ~Tabitha)

'A man who does not think and plan long ahead will find trouble right at his door.'
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Post Options Post Options   Thanks (1) Thanks(1)   Quote ViQueen24 Quote  Post ReplyReply Direct Link To This Post Posted: July 22 2020 at 2:46pm

I hope it works out.  I am skeptical that a vaccine is going to do what it doesn't seem our bodies do, that is, develop lasting immunity to Covid.  But I'll be happy to be wrong.

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Technophobe Quote  Post ReplyReply Direct Link To This Post Posted: July 22 2020 at 3:59pm

Virus antibodies fade fast but not necessarily protection

New research suggests that antibodies the immune system makes to fight the new coronavirus may only last a few months in people with mild illness

ByMARILYNN MARCHIONE AP Chief Medical Writer21 July 2020, 20:483 min read

New research suggests that antibodies the immune system makes to fight the new coronavirus may only last a few months in people with mild illness, but that doesn’t mean protection also is gone or that it won’t be possible to develop an effective vaccine.

“Infection with this coronavirus does not necessarily generate lifetime immunity,” but antibodies are only part of the story, said Dr. Buddy Creech, an infectious disease specialist at Vanderbilt University. He had no role in the work, published Tuesday in the         New England Journal of Medicine.

The immune system remembers how to make fresh antibodies if needed and other parts of it also can mount an attack, he said.

Antibodies are proteins that white blood cells called B cells make to bind to the virus and help eliminate it. The earliest ones are fairly crude but as infection goes on, the immune system becomes trained to focus its attack and to make more precise antibodies.

Dr. Otto Yang and others at the University of California, Los Angeles, measured these more precise antibodies in 30 patients diagnosed with COVID-19 and four housemates presumed to have the disease. Their average age was 43 and most had mild symptoms.

Researchers found that the antibodies had a half-life of 73 days, which means that half of them would be gone after that much time. It dovetails with a previous report from China also suggesting antibodies quickly fade.

The results “call for caution regarding antibody-based ‘immunity passports,’ herd immunity, and perhaps vaccine durability,” the California authors write. 

That’s true, Creech said, but other parts of the immune system also help confer protection. Besides churning out antibodies, B cells develop a memory so they know how to do that again if needed.

“They would get called into action very quickly when there’s a new exposure to the virus. It’s as if they lie dormant, just waiting,” he said.

Other white blood cells called T cells also are better able to attack the virus the next time they see it, Creech said.

Although circulating antibodies may not last long, what we need to know is if and how people remake antibodies if exposed to the coronavirus again and if they protect against another infection, Alison Criss, an immunologist at the University of Virginia, wrote in an email. “We also need to know if there is a protective T cell response” that reappears.

Vaccines, which provoke the immune system to make antibodies, might give longer-lasting protection than natural infection because they use purified versions of what stimulates that response, she noted. 

Creech agreed.

“This shouldn’t dissuade us from pursuing a vaccine,” he said. “Antibodies are only a part of the story.”

Source:   https://abcnews.go.com/Health/wireStory/virus-antibodies-fade-fast-necessarily-protection-71901700

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Post Options Post Options   Thanks (2) Thanks(2)   Quote Hazelpad Quote  Post ReplyReply Direct Link To This Post Posted: July 22 2020 at 5:42pm

THE PRESS ARE DOING MY HEAD IN.....Immune responses generated by vaccination and immune responses generated by natural wild type viral infection are 2 totally different things.  One does not correlate to the other.

I can run on,  so  my take  home message I have shortened  to the paragraph below.  I have written a longer explanation below that  for those interested in immunology.  


A Brief summary of my opinion.

What happens in a natural viral infection does not mirror what happens in vaccination.  Vaccines are designed to manipulated the immune system into generating  maximum protection.    Certain parts of the virus are engineered, enhanced and over represented in the vaccine because they are the areas which elicit stronger responses than the original  untouched  wild type virus.  ( these parts are called the pathogens dominant epitopes and vaccines are loaded with them).  Often  adjuvants are added to further enhance the vaccine  effects.  Also dosing regimes are tailored to maximise antibody production.  Route of vaccine administration also effects the level of response, intramuscular vs nasal etc.   Just because natural infection with wildtype virus has short lasting antibody responses, does not automatically correlate to future vaccine failure.  The immunological memory response generated by natural infection is very different to vaccine generated imrmune responses.  Vaccines often are designed to push  the immune response to a predominant Th2 antibody response where as natural viral responses often push to more of a TH1 cell mediated immune response ( more CD8+ killing than antibody killing).  Often natural viral infections are not dominated by antibodies, but our vaccines generated ones  intentionally are.

The press comparing wild type infection with vaccination outcome are comparing apples and oranges, they are not the same thing.  The aim of vaccination is not to follow natural infection, the aim of vaccine is to produce protection.  




Now further explanation for anyone interested.


Virus infect cells, they are known as intracellular pathogens. They are not like many bacteria which stay in bloodstream or infect  target organs etc, viruses need to go into cells for reproduction.  They are Intracellular parasites.

  Antibodies cant get into cells, their job is to mop up what's outside the cell.    They can catch viruses as they bud out and dash to another cell, but they are useless for killing the viruses reproducing inside the cell.

That is the job for  memory CD8+ T cells, Natural Killer cells, and CD4+ cells.  They literally  inject the viral infected cells with acid like the aliens in Alien movies.  They dont need antibodies for this.

 The infected cell dies after getting a dose of the aliens acid, but die in  a very controlled way,  it shrinks in on itself not allowing any virus inside to escape.  The shrinking dying cell sends out a signal, it dies a hero because that signal tells macrophages (large eating cell), to come along and  eat whats left of the poor cell and all those little viruses that were about to burst out of their host cell never do,  they die. 


Sometimes virus particles do escape and these are cleared by antibodies patrolling the bloodstream.  They act like those black blob things that are fired at Mr Incredible  in the first movie.  You know the scene that sees him running along the pathway.  Well imagine Mr Incredible is a virus and the black blobs are antibodies.  Then you get the picture.  Once the antibodies immobilize  the virus, again in come the large eating cells and they have a docking site for the antibodies, so they stick to the antibodies and eat their meal of antibody coated viral goulash.  The eating cells like the taste and get quite excited for more so they start to move faster searching for more and soon the virus is gone.

Both these tactics of the immune system ( often referred to as the immune systems 2 arms)  work together, the intracellular killing ( the alien like CD8+ cells) and the antibodies.  The  relative contribution each arm makes depends on the type of virus.  Sometimes antibodies are really really needed and other times they are a side show.   No matter what once the initial infectio is cleared there will be immunological memory.  Sometimes antibodies persist, sometimes memory CD8+ persist. 

Vaccine is different.  Vaccine is not normally a natural infection.  What goes on in a normal infection does not always correspond to the protection mechanisms generated in vaccines.  If antibodies wane in natural infection with COVID19 that does not mean they will automatically wane after vaccination.  Vaccines are designed to take what is calculated to be the most immunogenic part of the virus and get immunological memory against that.  

What happens in natural infection is not a perfect prediction of what will happen after immunisation.

 Even if the agent in the vaccine is close to the original virus, often the mode of entry or the time scale of multiple dosing is not.  The aim is not to follow natural infection, the aim of the vaccine is to produce protection.

The sort of protection you are aiming to obtain is not black and white.  Vaccination can range in effect from not developing any disease, or vaccinate to protect against full blown disease.  They are not the same.  Flu vaccine doesn't stop you getting infected with flu, it simply stops the infection progressing to a point you get really sick with it.  Instead yo probably just feel a bit tired for a day or 2 until the memory produced by the flu vaccine kicks in on Day 2 after exposure.

It also depends on what you need from a vaccine.  Take rabies, you need the antibodies high in the blood before that virus hits your body and reaches your nerve cells.  The prophylaxis travel  vaccine is designed to give abnormal elevated antibodies.  You want to catch the virus as soon as it enters the blood  stream before it can infect cells.  Natural infections often don't produce the level of antibodies that vaccine regimes do.

Natural Covid19 seems to produce lasting CD8+ CD4+ memory.  Antibody responses wane.  It is not such a big deal if you understand molecular immunology.  

  In practical terms it may simply mean on reexposure the immune responsememory restarts  after initial cell entry rather than bloodstream presence.   By this I mean the alienlike cells ( CD8+)  moves in first and Mr Incredible black blob's ( Bcells and antibodies)  take an extra day to appear.  Difference of a day tops.  So you might feel craggy for a day but by Day 2 antibody production and CMI restart.

Antibodies are not the immune system they are only part if it and in some infections they are not vital.  Infact bloody useless for some infections doing more harm that good and can skew the immune response in the wrong direction.  So every virus is different and not having lasting high antibody titres does not correlate to not having lasting immunity.  

The main take home message though is what happens in natural infection with wildtype virus does not predict what will happen in an immunisation reaction.


I am not saying vaccine will be possible but fed up with inaccurate pessimistic reporting in press.    

Anyway I like the Oxford vaccine that has just passed Phase 2 on 1700 people. It is now undergoing Phase 3 in Brazil etc.  UK are manufacturing 50 million doses and it uses a very traditional method.  Not keen on those using RNA new technology. 

Anyway bored you all enough.


 Hz x


New study reveals Oxford coronavirus vaccine produces strong immune response | University of Oxford

https://www.ox.ac.uk/news/2020-07-20-new-study-reveals-oxford-coronavirus-vaccine-produces-strong-immune-response

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Post Options Post Options   Thanks (0) Thanks(0)   Quote carbon20 Quote  Post ReplyReply Direct Link To This Post Posted: July 22 2020 at 10:41pm






Thanks Hazelpad,

I personally think all talk of a vaccine is to give people light at the end of the tunnel,

I don't think some people can cope with the situation as it is with out the thought of some way out..... 

I can't see a vaccine for the populous for a good 18 months if not longer.....

Everything we hear is an opinion, not a fact. Everything we see is a perspective, not the truth.🖖

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Post Options Post Options   Thanks (0) Thanks(0)   Quote EdwinSm, Quote  Post ReplyReply Direct Link To This Post Posted: July 22 2020 at 10:50pm

Thanks Hazel, that was a very useful posting.    

Although dealing mostly with vaccination, I found it encouraging on the question of re-infection - just because antibodies are low it does not mean all  protection is gone.  

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Technophobe Quote  Post ReplyReply Direct Link To This Post Posted: July 23 2020 at 1:07am

Thanks Hazel!

Personally, I'm quite hopefull where a vaccine is concerned, as the whole immunological world is looking for the first time.

Your essay makes me feel even more so.  Thanks!

I grock there are no guarantees, but the world has a lot of scientists in this field and they are all trying different methods/epitopes.  The antibody test (which seems to show a quick drop in protection) only looks for specific ones.   

ERCD
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Hazelpad Quote  Post ReplyReply Direct Link To This Post Posted: July 23 2020 at 1:49am

I am hopeful also.

Iwas pointing out that natural infection and vaccination do not always lead to the same level or type of immune response.  We cant measure how successful immunological memory is based on antibody production or antibody endurance alone.  That's what was doing my head in by the press.

However that's not to say I  think vaccination development for this disease is a done deal.

So time is needed

1) To evaluate the vaccines effectiveness and saftey.

2) Too evaluate what happens when a vaccinated person meets the wild tyoe virus (rechallenge).  Particularly will the antibody response generates by the vaccine be too little, or  perhaps the opposite, will it be too  strong and cause damage. (This happened with original SARS vaccine stratagies)

3) Is it immunogenic enough in older people and is it too immunogenic in young people.

4) Would the public trust it.

5) Large scale production.

So Carbon is right, it may be a long time yet.

I think there is hope though.  Just like a horse needing a clear round and there are many complex jumps still to get over.  We have hope of a clear round, the horse has done it in previous contests, but we cant guarantee a clear just yet.


Hx

 

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Technophobe Quote  Post ReplyReply Direct Link To This Post Posted: July 23 2020 at 5:18am

Good point!  Many horses  jumping, so fingers crossed - even if it is a puissance.

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Post Options Post Options   Thanks (1) Thanks(1)   Quote carbon20 Quote  Post ReplyReply Direct Link To This Post Posted: July 23 2020 at 6:08am





Plan for worst 

Hope for best.....

Forgive me I dont mean to be a pessimist,

Rather think I'm a realist....

In my job I see people really critical of small insignificant things.....

I often think "what are you going to do when the S..t hits the fan...."

It has and I don't think many will be able to cope......

Now a days it's to easy not  to face up to things,

Have a row,just unfriened them....... 

Change channel if you don't like the news.....

Finding it all very interesting......

Keep safe all 

Everything we hear is an opinion, not a fact. Everything we see is a perspective, not the truth.🖖

Marcus Aurelius
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