[ExI] COVID super immunity
stathisp at gmail.com
Sat Oct 23 14:30:03 UTC 2021
On Sat, 23 Oct 2021 at 16:24, Sherry Knepper via extropy-chat <
extropy-chat at lists.extropy.org> wrote:
> And how can it be certain the immunity is permanent, meaning if the person
> dies it will not be from COVID-19?
> Sent from Yahoo Mail on Android
Follow up and compare people who have had two vaccine shots, three shots,
or two shots and COVID-19 and monitor for coronavirus infection. It should
be fairly easy to find a large enough sample given that there have been
hundreds of millions of COVID-19 cases and billions of vaccines given.
> On Sat, Oct 23, 2021 at 1:16 AM, Sherry Knepper
> <guessmyneeds at yahoo.com> wrote:
> But how many shots are needed for the vaccine requirement for the 100%
> covid19 immunity?
> Sent from Yahoo Mail on Android
> On Thu, Oct 21, 2021 at 1:02 PM, Stuart LaForge via extropy-chat
> <extropy-chat at lists.extropy.org> wrote:
> According this article in Nature, people who have caught and survived
> COVID infection and subsequently get the COVID vaccine develop super
> immunity aka hybrid immunity. This super immunity protects the patient
> against every POSSIBLE COVID strain. They tested this by creating
> every possible mutation of the viral spike protein and testing patient
> antibodies against them. People who are super immune seem protected
> against all strains of COVID past, present, and future. Scientists are
> hoping a third vaccine dose creates the same kind of super immunity as
> having recovered the disease and getting vaccinated.
> Around a year ago — before Delta and other variants entered the
> COVID-19 lexicon — virologists Theodora Hatziioannou and Paul
> Bieniasz, both at the Rockefeller University in New York City, set out
> to make a version of a key SARS-CoV-2 protein with the ability to
> dodge all the infection-blocking antibodies our body makes.
> The goal was to identify the parts of spike — the protein SARS-CoV-2
> uses to infect cells — that are targeted by these neutralizing
> antibodies in order to map a key part of our body's attack on the
> virus. So the researchers mixed and matched potentially concerning
> mutations identified in lab experiments and circulating viruses, and
> tested their Franken-spikes in harmless ‘pseudotype’ viruses incapable
> of causing COVID-19. In a study published this September in Nature1,
> they reported that a spike mutant containing 20 changes was fully
> resistant to neutralizing antibodies made by most of the people tested
> who had been either infected or vaccinated — but not to everyone’s.
> Those who had recovered from COVID-19 months before receiving their
> jabs harboured antibodies capable of defanging the mutant spike, which
> displays much more resistance to immune attack than any known
> naturally occurring variant. These peoples’ antibodies even blocked
> other types of coronaviruses. “It’s very likely they will be effective
> against any future variant that SARS-CoV-2 throws against them,” says
> As the world watches out for new coronavirus variants, the basis of
> such ‘super-immunity’ has become one of the pandemic’s great
> mysteries. Researchers hope that, by mapping the differences between
> the immune protection that comes from infection compared with that
> from vaccination, they can chart a safer path to this higher level of
> “It has implications on boosters and how our immune responses are
> primed for the next variant that emerges,” says Mehul Suthar, a
> virologist at Emory University in Atlanta, Georgia. “We’re flying by
> the seat of our pants trying to figure this stuff out.”
> Hybrid immunity
> Not long after countries began rolling out vaccines, researchers
> started noticing unique properties of the vaccine responses of people
> who had previously caught and recovered from COVID-19. “We saw that
> the antibodies come up to these astronomical levels that outpace what
> you get from two doses of vaccine alone,” says Rishi Goel, an
> immunologist at the University of Pennsylvania in Philadelphia who is
> part of a team studying super-immunity — or ‘hybrid immunity’, as most
> scientists call it.
> Initial studies of people with hybrid immunity found that their serum
> — the antibody-containing portion of blood — was far better able to
> neutralize immune-evading strains, such as the Beta variant identified
> in South Africa, and other coronaviruses, compared with ‘naive’
> vaccinated individuals who had never encountered SARS-CoV-22. It
> wasn’t clear whether this was just due to the high levels of
> neutralizing antibodies, or to other properties.
> The most recent studies suggest that hybrid immunity is, at least
> partly, due to immune players called memory B cells. The bulk of
> antibodies made after infection or vaccination come from short-lived
> cells called plasmablasts, and antibody levels fall when these cells
> inevitably die off. Once plasmablasts are gone, the main source of
> antibodies becomes much rarer memory B cells that are triggered by
> either infection or vaccination.
> International COVID-19 trial to restart with focus on immune responses
> Some of these long-lived cells make higher-quality antibodies than
> plasmablasts, says Michel Nussenzweig, an immunologist at the
> Rockefeller. That’s because they evolve in organs called lymph nodes,
> gaining mutations that help them to bind more tightly to the spike
> protein over time. When people who recovered from COVID-19 are
> re-exposed to SARS-CoV-2’s spike, these cells multiply and churn out
> more of these highly potent antibodies.
> “You get a sniff of antigen, in this case of mRNA vaccine, and those
> cells just explode,” says Goel. In this way, a first vaccine dose in
> someone who has previously been infected is doing the same job as a
> second dose in someone who has never had COVID-19.
> Potent antibodies
> Differences between the memory B cells triggered by infection and
> those triggered by vaccination — as well as the antibodies they make —
> might also underlie the heightened responses of hybrid immunity.
> Infection and vaccination expose the spike protein to the immune
> system in vastly different ways, Nussenzweig says.
> In a series of studies3,4,5, Nussenzweig’s team, which includes
> Hatziioannou and Bieniasz, compared the antibody responses of infected
> and vaccinated people. Both lead to the establishment of memory B
> cells that make antibodies that have evolved to become more potent,
> but the researchers suggest this occurs to a greater extent after
> The team isolated hundreds of memory B cells — each making a unique
> antibody — from people at various time points after infection and
> vaccination. Natural infection triggered antibodies that continued to
> grow in potency and their breadth against variants for a year after
> infection, whereas most of those elicited by vaccination seemed to
> stop changing in the weeks after a second dose. Memory B cells that
> evolved after infection were also more likely than those from
> vaccination to make antibodies that block immune-evading variants such
> as Beta and Delta.
> Health-care workers get the Pfizer-BioNTech COVID-19 vaccination in
> Portland, Oregon.
> Health-care workers receiving the Pfizer–BioNTech COVID-19 vaccine.
> People who get the vaccine after infection are less likely to test
> positive for COVID-19 than individuals with no history of
> infection.Credit: Paula Bronstein/Getty
> A separate study found that, compared with mRNA vaccination, infection
> leads to a pool of antibodies that recognize variants more evenly by
> targeting diverse regions of spike6. The researchers also found that
> people with hybrid immunity produced consistently higher levels of
> antibodies, compared with never-infected vaccinated people, for up to
> seven months. Antibody levels were also more stable in people with
> hybrid immunity, reports the team led by immunologist Duane Wesemann
> at Harvard Medical School in Boston, Massachusetts.
> ‘Not surprising’
> Many studies of hybrid immunity haven’t followed naive vaccine
> recipients for as long as those who recovered from COVID-19, and it’s
> possible their B cells will make antibodies that gain potency and
> breadth with more time, additional vaccine doses, or both, researchers
> say. It can take months for a stable pool of memory B cells to
> establish itself and mature.
> “It’s not surprising that people infected and vaccinated are getting a
> nice response,” says Ali Ellebedy, a B-cell immunologist at Washington
> University in St. Louis, Missouri. “We are comparing someone who
> started the race three to four months ago to someone who started the
> race now.”
> There is some evidence that people who received both jabs without
> previously being infected seem to be catching up. Ellebedy’s team
> collected lymph-node samples from mRNA-vaccinated individuals and
> found signs that some of their memory B cells triggered by the
> vaccination were gaining mutations, up to 12 weeks after the second
> dose, that enabled them to recognize diverse coronaviruses, including
> some that cause common colds7.
> Goel, University of Pennsylvania immunologist John Wherry and their
> colleagues found signs that six months after vaccination, memory B
> cells from naive individuals were continuing to grow in number and
> evolve greater capacity to neutralize variants8. Antibody levels fell
> after vaccination, but these cells should start cranking out
> antibodies if they encounter SARS-CoV-2 again. “The reality is you
> have a pool of high-quality memory B cells that are there to protect
> you if you ever see this antigen again,” Goel says.
> Booster benefits
> A third vaccine dose might allow people who haven't been infected to
> achieve the benefits of hybrid immunity, says Matthieu Mahévas, an
> immunologist at the Necker Institute for Sick Children in Paris. His
> team found that some of the memory B cells from naive vaccine
> recipients could recognize Beta and Delta, two months after
> vaccination9. “When you boost this pool, you can clearly imagine you
> will generate potent neutralizing antibodies against variants,”
> Mahévas says.
> Extending the interval between vaccine doses could also mimic aspects
> of hybrid immunity. In 2021, amid scarce vaccine supplies and a surge
> in cases, officials in the Canadian province of Quebec recommended a
> 16-week interval between first and second doses (since reduced to 8
> A team co-led by Andrés Finzi, a virologist at the University of
> Montreal, Canada, found that people who received this regimen had
> SARS-CoV-2 antibody levels similar to those in people with hybrid
> immunity10. These antibodies could neutralize a swathe of SARS-CoV-2
> variants — as well as the virus behind the 2002–04 SARS epidemic. “We
> are able to bring naive people to almost the same level as previously
> infected and vaccinated, which is our gold standard,” says Finzi.
> How ‘killer’ T cells could boost COVID immunity in face of new variants
> Understanding the mechanism behind hybrid immunity will be key to
> emulating it, say scientists. The latest studies focus on antibody
> responses made by B cells, and it’s likely that T-cell responses to
> vaccination and infection behave differently. Natural infection also
> triggers responses against viral proteins other than spike — the
> target of most vaccines. Nussenzweig wonders whether other factors
> unique to natural infection are crucial. During infection, hundreds of
> millions of viral particles populate the airways, encountering immune
> cells that regularly visit nearby lymph nodes, where memory B cells
> mature. Viral proteins stick around in the gut of some people months
> after recovery, and it’s possible that this persistence helps B cells
> hone their responses to SARS-CoV-2.
> Researchers say that it is also important to determine the real-world
> effects of hybrid immunity. A study from Qatar suggests that people
> who get Pfizer–BioNTech’s mRNA vaccine after infection are less likely
> to test positive for COVID-19 than are individuals with no history of
> infection11. Hybrid immunity might also be responsible for falling
> case numbers across South America, says Gonzalo Bello Bentancor, a
> virologist at the Oswaldo Cruz Institute in Rio de Janeiro, Brazil.
> Many South American countries experienced very high infection rates
> earlier in the pandemic, but have now vaccinated a large proportion of
> their populations. It's possible that hybrid immunity is better than
> the immunity from vaccination alone at blocking transmission, says
> Bello Bentancor.
> As breakthrough infections caused by the Delta variant stack up,
> researchers including Nussenzweig are keen to study the immunity in
> people who were infected after their COVID-19 vaccinations, rather
> than before. An individual’s first exposure to influenza virus biases
> their responses to subsequent exposures and vaccinations — a
> phenomenon called original antigenic sin — and researchers want to
> know if this occurs with SARS-CoV-2.
> Those studying hybrid immunity stress that — whatever the potential
> benefits — the risks of a SARS-CoV-2 infection mean that it should be
> avoided. “We are not inviting anybody to get infected and then
> vaccinated to have a good response,” says Finzi. “Because some of them
> will not make it through.”
> Nature 598, 393-394 (2021)
> doi: https://doi.org/10.1038/d41586-021-02795-x
> Stuart LaForge
> extropy-chat mailing list
> extropy-chat at lists.extropy.org
> extropy-chat mailing list
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