Tavo @tavoglc@social.cleverlibre.org

"COVID’s impact on the elderly was worrisome, Leonardi noted in 2020, “because as we age, we don’t produce many, if any, T cells… You can’t turn the clock back on T cells. Too many challenges, and they exhaust and senesce. Not to mention, the virus will mutate and escape without vaccines.”

Turns out that Leonardi was right again."

"six months before COVID vaccines became available & ...before...the virus would evolve to achieve “breakthrough infections” despite vaccines, Leonardi voiced this grim concern:

“In the worst case scenario, in a situation where this virus sufficiently mutates and perpetuates, I fear a world where most of the aged succumb to complications of COVID.”

Many life expectancy experts said such speculation was ridiculous. (They have since deleted their tweets.)"

"Even Leonardi-slamming Antonio Bertoletti, recently offered a more nuanced perspective on T cells and COVID in the publication Cell than he has on Twitter.

“It is therefore possible that mechanisms of functional dysregulation in T cells might drive the exacerbated inflammatory events that characterize severe COVID-19 and even some aspects of the prolonged pathology observed in some COVID-19 convalescents.” He does not mention Leonardi."

"Swedish researchers confirmed again what Leonardi speculated about two years ago: that people with severe COVID showed long-lasting effects on the immune system for seven to eight months. “The effects on the T cells of the immune system are interesting and mixed,” reported Marie Larsson....

“Some of them are still activated long after the disease episode, while others are ‘fatigued’ and cannot function normally. We see similar effects on patients with a chronic HIV infection."

"In many respects people with Long COVID closely resemble patients with chronic fatigue syndrome -- another form of immune dysregulation brought on by chronic viral infection.  

Dr. Anthony Leonardi: ‘Whoever says continued exposure is better for the individual and the antibody responses stands contrary to the new data and is overly optimistic. It is this unbridled optimism about infection and the immunity it confers that helped get us into this complete mess.’"

"Iwasaki has hypothesized that Long COVID can be caused by persistent virus infection, viral remnants, or an autoimmune reaction. In a recent study that closely looked at the immune systems of 99 patients with long COVID, Iwasaki’s team found exactly what Leonardi had first hypothesized: exhausted T cells that suggested the patients were fighting an active chronic infection. The strength of T-cell exhaustion also corresponded with the reactivation of Epstein Bar virus in patients."

""In 2022 a Chinese study reported that COVID infects and kills T cells contributing to immune dysfunction that favors viral persistence in the body. Two researchers commenting on the study’s implications noted that infected T cells “are not only compromised in their ability to control viral infection, but they can also transport viruses to other parts of the body through the bloodstream, causing the spread of infection, affecting various organs and parts of the body.”"

"Peter Doherty speculated that ... findings “could reflect a continuing confrontation between persistent virus and immune cells and antibodies that are trying to eliminate it from our bodies, but are not quite succeeding in doing so.”"

"Australian researchers have reported similar intriguing findings after looking at the blood profiles of patients suffering from long COVID and comparing them to healthy controls. They found that “immunological dysfunction persisted for eight months after mild to moderate” infection including indicators of “chronic T cell activation and potentially exhaustion.” They also found that people with long COVID were missing naive T cells, just as Leonardi had warned."

""What they discovered surprised them and appears counterintuitive. Patients with severe disease appeared to have competent T cell memory to fight off reinfection while mild cases suffered from T cell exhaustion. Exhausted T cells lose their ability to fight off viruses or cancer for that matter.
“People who have severe disease are likely to end up with a good number of memory cells,” said... Vijayanand.... “People with milder disease have memory cells, but they seem exhausted and dysfunctional"

""One of the first hints that COVID could severely mess with the immune system, particularly in severe cases, came in a small study that autopsied 11 people who died of the infection in the summer of 2020.  The dead didn’t have so-called germinal centres or places in the spleen and lymph glands where immune cells learn how to mount a long-lasting attack against a biological invader. 

In other words the immune system didn’t do what it supposed to do: successfully defeat the infection"

"He speculated that COVID reinfections could be big trouble and should be avoided.

Given the virus’s ability to undermine and age the immune system, he argued that exposing children repeatedly to a virus that impairs the immune system and causes vascular disease and brain shrinkage was bad policy. 

And, very early in the pandemic, he argued that herd immunity was wishful thinking and could not be achieved."

"For starters, Leonardi warned that the virus undermined and aged the immune system by hyperactivating and exhausting T cells. This overstimulation could in turn damage organs including the heart, brain and the kidneys.

He predicted that the pandemic would reduce life expectancy around the world, most harming people aged 50 and over.

He hypothesized that the virus, by harming the immune system, could make people more vulnerable to other infections and cancers."

"“The reasons Anthony was so broadly attacked was because he undermined the position that once you’ve been infected, you don’t have to worry again.”...“He recognized early on that our idea of how the immune system should work with a virus, wasn’t going to be the case with COVID, and he was right.”"

"“His arguments threatened to undermine the narratives of those people minimizing the pandemic,” Gregory told The Tyee. “If previous infection dampens the immune system and does not strengthen it, it undermines the popular notion that we should let the virus rip.” "

""Bertoletti... posted a Nature study on healthcare workers claiming that it showed that “exposure [to COVID] broadens T-cell repertoire,” and that there was no problem with exhaustion.

However, the paper only looked at working age people and did not include individuals with long COVID in which chronic and persistent infection inflames the immune system."

"“Reminder that not every crank is Galileo..." One of the barbs often tossed at Leonardi by critics is that he is not ensconced in a lab churning out results from experiments, so he doesn’t really belong to the club of researchers seriously trying to crack COVID. Leonardi is in fact a PhD accredited immunologist currently pursuing a master’s degree in public health"

""The uproar reached a fever peak this year when Leonardi speculated that repeated COVID infections could exhaust T cells in people 50 years or older leading to a blunted immune response. (Chronic infections such as HIV or Epstein-Bar virus typically exhaust T cells.)

Leonardi first offered this opinion in August of 2020 but it gained currency as reinfections skyrocketed with Omicron."

"What if the virus wears down T cells... increasingly with each reinfection?
...The exhaustion of those hyperactivated T cells... implies they aren’t winning the battle against viral proteins they are supposed to defeat
...In other words, argues Leonardi, T cells are becoming hyperactivated by SARS-CoV-2 & are prematurely aging, harming organs, & becoming exhausted trying to rid the body of an immune-evasive virus."

"in April 2021, Leonardi stated there would be “no collective immunity by infection” because “each incidence of infection is a net negative and a poison pill. It resets the tally of immunity by contributing to evolution and immune escape.”
The scientific consensus now clearly supports Leonardi. Neither infections nor vaccines achieved herd immunity because of the immune evasive nature of the virus. Most scientists now regard the concept of herd immunity as a mirage."