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Coronavirus: how T cells are involved and what it might mean for vaccine development

Coronavirus: how T cells are involved and what it might mean for vaccine development

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Developing a vaccine is difficult at the best of times, but rarely have we been in a situation where basic knowledge about a virus has to be acquired so directly alongside the race to eradicate it. To understand how difficult this task is, we must appreciate the complexity of how our immune system responds to an infection.

The part of the immune response that can target germs precisely and provide long-term protection is called the adaptive immune response. Two types of white blood cell are important in this: T cells and B cells. These cells work together to orchestrate a targeted immune response. But the way they recognise and deal with germs is different.

Both T cells and B cells have an important receptor molecule on their surface, not so imaginatively called the T cell receptor and the B cell receptor. B cell receptors lock onto unique structural components of a germ, or an infected cell, directly. T cells, on the other hand, need other immune cells to chew up and present parts of the germ in small fragments, which can then be scrutinised.

So for any given germ, T cells and B cells see it differently. They also respond in different ways. Even T cells don’t just do one thing. Some – the cytotoxic T cells – attack infected cells directly, while others – the T helper cells – support immune responses by helping B cells produce antibodies.

All this complexity serves to attack different germs in different ways and helps prevent unintended damage to our body’s healthy cells and tissues, as it provides multi-step checks before an immune response is fully activated.

Getting T cells and B cells to respond to a germ takes time – usually several days following the initial infection. Once T and B cells have been sent to deal with a germ, the immune response subsides and long-lived memory versions of T cells and B cells are retained so that the appropriate response can be mounted much faster if the same germ is encountered again.

Vaccines try to mimic this natural process by provoking the development of long-lived memory T cells and B cells, without triggering the symptoms of a real infection. It’s not the case, though, that each type of vaccine stimulates a similar immune response. There are many types of vaccine and each will trigger a cascade of events that stimulate the immune system in a particular way.

Most vaccines will target B cells and the types of T cells that support antibody production. Yet for some infections, the antibody response may not be enough. In such cases, vaccines can also be developed to promote cytotoxic T cell activity, or perhaps a combination of both antibody and cytotoxic T cell immune responses.

Understanding the type of immune response that works best against a particular infection is important for vaccine design. And we are still learning about our adaptive immune response to the novel coronavirus.

Looking beyond spike proteins

The virus can be pictured as a small spiky ball that encapsulates genetic material. Many vaccines currently being tested aim to create an immune reaction against the protein molecules that make up the outer spikes. The spikes are critical for how the virus gets into human cells, so antibodies that lock onto those structures might stop the virus from entering cells. But the evidence is mounting that targeting other parts of the virus might also be useful.

A coronavirus with its telltale spike proteins jutting out from the surface. Kateryna Kon/Shutterstock

A recent study – which has yet to be peer-reviewed – assessed T cell memory responses in patients who had recovered from mild and severe COVID-19. Patients who had severe symptoms showed a stronger and more varied T cell response. Their T cells reacted to the virus’s spikes, but also to internal components of the virus – which have cumbersome names such as “receptor binding domains” and “nucleoproteins”.

In detail, cytotoxic T cells that could attack virus-infected cells directly seemed to target internal parts of the virus, whereas T helper cells, which support antibody production, reacted to viral surface molecules.

Having an immune response capable of detecting different aspects of a virus might make it harder for the virus to escape being detected. This is important to factor into the design of vaccines: maybe we will need cytotoxic T cells and B cells to target different parts of the virus. Indeed, a study in macaques showed that a vaccine candidate targeting only the viral spike protein induced good, but not complete, protection.

Vaccines that do not induce full immunity are still important, of course, because they can lessen the severity or duration of infection. This is why designing vaccines is a complex process that requires a good understanding of immune responses.

We are still learning about COVID-19 and questions remain as to whether complete protection against it is even possible.

Issues still to be tackled

Another area of debate is whether some protection can arise from being infected with another coronavirus. There is some similarity between the version of coronavirus causing the current pandemic and others that cause a mild cold.

Some studies show a cross-reactivity, but others show none. Differences in these results may be down to how immune responses were analysed, or variations between people who could have had different prior exposures. Either way, such conflicting observations highlight the complexities involved.

Concerns have also been raised about the possibility of vaccines eliciting a response that could, at least in principle, produce antibodies that help the virus get into cells – a phenomenon known as antibody dependent enhancement.

The pressure to develop a vaccine is huge. The rush must not override the need for safety. There are other issues we must also tackle – not least, the manufacturing and fair distribution of anything that works. But right now, understanding the human immune response to this virus is our best hope and our greatest challenge.

Daniel M Davis is the author of two books about the immune system, The Beautiful Cure (Vintage) and The Compatibility Gene (Penguin). He receives funding from the Wellcome Trust, GSK and Continuum Life Sciences.

Sheena Cruickshank does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

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Survey Shows Declining Concerns Among Americans About COVID-19

Survey Shows Declining Concerns Among Americans About COVID-19

A new survey reveals that only 20% of Americans view covid-19 as "a major threat"…

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Survey Shows Declining Concerns Among Americans About COVID-19

A new survey reveals that only 20% of Americans view covid-19 as "a major threat" to the health of the US population - a sharp decline from a high of 67% in July 2020.

(SARMDY/Shutterstock)

What's more, the Pew Research Center survey conducted from Feb. 7 to Feb. 11 showed that just 10% of Americans are concerned that they will  catch the disease and require hospitalization.

"This data represents a low ebb of public concern about the virus that reached its height in the summer and fall of 2020, when as many as two-thirds of Americans viewed COVID-19 as a major threat to public health," reads the report, which was published March 7.

According to the survey, half of the participants understand the significance of researchers and healthcare providers in understanding and treating long COVID - however 27% of participants consider this issue less important, while 22% of Americans are unaware of long COVID.

What's more, while Democrats were far more worried than Republicans in the past, that gap has narrowed significantly.

"In the pandemic’s first year, Democrats were routinely about 40 points more likely than Republicans to view the coronavirus as a major threat to the health of the U.S. population. This gap has waned as overall levels of concern have fallen," reads the report.

More via the Epoch Times;

The survey found that three in ten Democrats under 50 have received an updated COVID-19 vaccine, compared with 66 percent of Democrats ages 65 and older.

Moreover, 66 percent of Democrats ages 65 and older have received the updated COVID-19 vaccine, while only 24 percent of Republicans ages 65 and older have done so.

“This 42-point partisan gap is much wider now than at other points since the start of the outbreak. For instance, in August 2021, 93 percent of older Democrats and 78 percent of older Republicans said they had received all the shots needed to be fully vaccinated (a 15-point gap),” it noted.

COVID-19 No Longer an Emergency

The U.S. Centers for Disease Control and Prevention (CDC) recently issued its updated recommendations for the virus, which no longer require people to stay home for five days after testing positive for COVID-19.

The updated guidance recommends that people who contracted a respiratory virus stay home, and they can resume normal activities when their symptoms improve overall and their fever subsides for 24 hours without medication.

“We still must use the commonsense solutions we know work to protect ourselves and others from serious illness from respiratory viruses, this includes vaccination, treatment, and staying home when we get sick,” CDC director Dr. Mandy Cohen said in a statement.

The CDC said that while the virus remains a threat, it is now less likely to cause severe illness because of widespread immunity and improved tools to prevent and treat the disease.

Importantly, states and countries that have already adjusted recommended isolation times have not seen increased hospitalizations or deaths related to COVID-19,” it stated.

The federal government suspended its free at-home COVID-19 test program on March 8, according to a website set up by the government, following a decrease in COVID-19-related hospitalizations.

According to the CDC, hospitalization rates for COVID-19 and influenza diseases remain “elevated” but are decreasing in some parts of the United States.

Tyler Durden Sun, 03/10/2024 - 22:45

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Rand Paul Teases Senate GOP Leader Run – Musk Says “I Would Support”

Rand Paul Teases Senate GOP Leader Run – Musk Says "I Would Support"

Republican Kentucky Senator Rand Paul on Friday hinted that he may jump…

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Rand Paul Teases Senate GOP Leader Run - Musk Says "I Would Support"

Republican Kentucky Senator Rand Paul on Friday hinted that he may jump into the race to become the next Senate GOP leader, and Elon Musk was quick to support the idea. Republicans must find a successor for periodically malfunctioning Mitch McConnell, who recently announced he'll step down in November, though intending to keep his Senate seat until his term ends in January 2027, when he'd be within weeks of turning 86. 

So far, the announced field consists of two quintessential establishment types: John Cornyn of Texas and John Thune of South Dakota. While John Barrasso's name had been thrown around as one of "The Three Johns" considered top contenders, the Wyoming senator on Tuesday said he'll instead seek the number two slot as party whip. 

Paul used X to tease his potential bid for the position which -- if the GOP takes back the upper chamber in November -- could graduate from Minority Leader to Majority Leader. He started by telling his 5.1 million followers he'd had lots of people asking him about his interest in running...

...then followed up with a poll in which he predictably annihilated Cornyn and Thune, taking a 96% share as of Friday night, with the other two below 2% each. 

Elon Musk was quick to back the idea of Paul as GOP leader, while daring Cornyn and Thune to follow Paul's lead by throwing their names out for consideration by the Twitter-verse X-verse. 

Paul has been a stalwart opponent of security-state mass surveillance, foreign interventionism -- to include shoveling billions of dollars into the proxy war in Ukraine -- and out-of-control spending in general. He demonstrated the latter passion on the Senate floor this week as he ridiculed the latest kick-the-can spending package:   

In February, Paul used Senate rules to force his colleagues into a grueling Super Bowl weekend of votes, as he worked to derail a $95 billion foreign aid bill. "I think we should stay here as long as it takes,” said Paul. “If it takes a week or a month, I’ll force them to stay here to discuss why they think the border of Ukraine is more important than the US border.”

Don't expect a Majority Leader Paul to ditch the filibuster -- he's been a hardy user of the legislative delay tactic. In 2013, he spoke for 13 hours to fight the nomination of John Brennan as CIA director. In 2015, he orated for 10-and-a-half-hours to oppose extension of the Patriot Act

Rand Paul amid his 10 1/2 hour filibuster in 2015

Among the general public, Paul is probably best known as Capitol Hill's chief tormentor of Dr. Anthony Fauci, who was director of the National Institute of Allergy and Infectious Disease during the Covid-19 pandemic. Paul says the evidence indicates the virus emerged from China's Wuhan Institute of Virology. He's accused Fauci and other members of the US government public health apparatus of evading questions about their funding of the Chinese lab's "gain of function" research, which takes natural viruses and morphs them into something more dangerous. Paul has pointedly said that Fauci committed perjury in congressional hearings and that he belongs in jail "without question."   

Musk is neither the only nor the first noteworthy figure to back Paul for party leader. Just hours after McConnell announced his upcoming step-down from leadership, independent 2024 presidential candidate Robert F. Kennedy, Jr voiced his support: 

In a testament to the extent to which the establishment recoils at the libertarian-minded Paul, mainstream media outlets -- which have been quick to report on other developments in the majority leader race -- pretended not to notice that Paul had signaled his interest in the job. More than 24 hours after Paul's test-the-waters tweet-fest began, not a single major outlet had brought it to the attention of their audience. 

That may be his strongest endorsement yet. 

Tyler Durden Sun, 03/10/2024 - 20:25

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The Great Replacement Loophole: Illegal Immigrants Score 5-Year Work Benefit While “Waiting” For Deporation, Asylum

The Great Replacement Loophole: Illegal Immigrants Score 5-Year Work Benefit While "Waiting" For Deporation, Asylum

Over the past several…

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The Great Replacement Loophole: Illegal Immigrants Score 5-Year Work Benefit While "Waiting" For Deporation, Asylum

Over the past several months we've pointed out that there has  been zero job creation for native-born workers since the summer of 2018...

... and that since Joe Biden was sworn into office, most of the post-pandemic job gains the administration continuously brags about have gone foreign-born (read immigrants, mostly illegal ones) workers.

And while the left might find this data almost as verboten as FBI crime statistics - as it directly supports the so-called "great replacement theory" we're not supposed to discuss - it also coincides with record numbers of illegal crossings into the United States under Biden.

In short, the Biden administration opened the floodgates, 10 million illegal immigrants poured into the country, and most of the post-pandemic "jobs recovery" went to foreign-born workers, of which illegal immigrants represent the largest chunk.

Asylum seekers from Venezuela await work permits on June 28, 2023 (via the Chicago Tribune)

'But Tyler, illegal immigrants can't possibly work in the United States whilst awaiting their asylum hearings,' one might hear from the peanut gallery. On the contrary: ever since Biden reversed a key aspect of Trump's labor policies, all illegal immigrants - even those awaiting deportation proceedings - have been given carte blanche to work while awaiting said proceedings for up to five years...

... something which even Elon Musk was shocked to learn.

Which leads us to another question: recall that the primary concern for the Biden admin for much of 2022 and 2023 was soaring prices, i.e., relentless inflation in general, and rising wages in particular, which in turn prompted even Goldman to admit two years ago that the diabolical wage-price spiral had been unleashed in the US (diabolical, because nothing absent a major economic shock, read recession or depression, can short-circuit it once it is in place).

Well, there is one other thing that can break the wage-price spiral loop: a flood of ultra-cheap illegal immigrant workers. But don't take our word for it: here is Fed Chair Jerome Powell himself during his February 60 Minutes interview:

PELLEY: Why was immigration important?

POWELL: Because, you know, immigrants come in, and they tend to work at a rate that is at or above that for non-immigrants. Immigrants who come to the country tend to be in the workforce at a slightly higher level than native Americans do. But that's largely because of the age difference. They tend to skew younger.

PELLEY: Why is immigration so important to the economy?

POWELL: Well, first of all, immigration policy is not the Fed's job. The immigration policy of the United States is really important and really much under discussion right now, and that's none of our business. We don't set immigration policy. We don't comment on it.

I will say, over time, though, the U.S. economy has benefited from immigration. And, frankly, just in the last, year a big part of the story of the labor market coming back into better balance is immigration returning to levels that were more typical of the pre-pandemic era.

PELLEY: The country needed the workers.

POWELL: It did. And so, that's what's been happening.

Translation: Immigrants work hard, and Americans are lazy. But much more importantly, since illegal immigrants will work for any pay, and since Biden's Department of Homeland Security, via its Citizenship and Immigration Services Agency, has made it so illegal immigrants can work in the US perfectly legally for up to 5 years (if not more), one can argue that the flood of illegals through the southern border has been the primary reason why inflation - or rather mostly wage inflation, that all too critical component of the wage-price spiral  - has moderated in in the past year, when the US labor market suddenly found itself flooded with millions of perfectly eligible workers, who just also happen to be illegal immigrants and thus have zero wage bargaining options.

None of this is to suggest that the relentless flood of immigrants into the US is not also driven by voting and census concerns - something Elon Musk has been pounding the table on in recent weeks, and has gone so far to call it "the biggest corruption of American democracy in the 21st century", but in retrospect, one can also argue that the only modest success the Biden admin has had in the past year - namely bringing inflation down from a torrid 9% annual rate to "only" 3% - has also been due to the millions of illegals he's imported into the country.

We would be remiss if we didn't also note that this so often carries catastrophic short-term consequences for the social fabric of the country (the Laken Riley fiasco being only the latest example), not to mention the far more dire long-term consequences for the future of the US - chief among them the trillions of dollars in debt the US will need to incur to pay for all those new illegal immigrants Democrat voters and low-paid workers. This is on top of the labor revolution that will kick in once AI leads to mass layoffs among high-paying, white-collar jobs, after which all those newly laid off native-born workers hoping to trade down to lower paying (if available) jobs will discover that hardened criminals from Honduras or Guatemala have already taken them, all thanks to Joe Biden.

Tyler Durden Sun, 03/10/2024 - 19:15

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