Thread by @loscharlos

“A growing number of scientists believe the SARS-CoV-2 virus may be subtly altering our immune systems. If correct, their hypothesis will change how we understand everything from RSV to shingles to sepsis.”

“It’s certainly impacting our immune health & probably.. overall health”

“SARS-CoV-2 is linked to ‘an unusually high level of *indiscriminate* killing of T cells’.. reminiscent of measles, which can cause immune amnesia by depleting memory B cell, leaving people vulnerable to pathogens they were previously immune to.” bmj.com/content/390/bm…

“‘Immunity debt,’ a theory to explain the global surge in non-covid infections since pandemic restrictions were lifted, is increasingly being challenged by emerging evidence.” bmj.com/content/390/bm…

“I can count on my two hands the number of times I’d ever seen mycoplasma pneumoniae before 2023,” says Samira Jeimy, clinical immunologist at the University of Western Ontario. “All of a sudden I feel like everybody has it.”bmj.com/content/390/bm…

“Malgorzata Gasperowicz, a Calgary based developmental biologist, says that if immunity debt fully explained rising infection counts we’d expect to see a uniform rebound across all pathogens. But we don’t, she says.” bmj.com/content/390/bm…

“Wolfgang Leitner, chief of the Innate Immunity Section at @NIAIDNews speculates that covid-19 may somehow impair the immune system’s ‘memory’ of past infections, potentially making even healthy people more vulnerable to future pathogens.”
bmj.com/content/390/bm…

@NIAIDNews “A 2024 study of more than 4000 viral cases from Ontario, Canada, found higher rates of bacterial infections in people recovering from covid-19 than in those recovering from influenza or RSV” bmj.com/content/390/bm…

@NIAIDNews “Jeimy says that many infants and toddlers admitted to hospital with rare infections since 2022 weren’t yet born when pandemic restrictions were in place.. therefore couldn’t be experiencing immunity debt. They were, however, likely exposed to SARS-CoV-2.” bmj.com/content/390/bm…

@NIAIDNews “Brazilian researchers found covid-19 triggered a sharp rise in T cell exhaustion & cellular ageing.. the strongest effects were seen in CD8+ T cells, which suppress latent viruses such as EBV and VZV. These effects were seen even after mild infections.” bmj.com/content/390/bm…

@NIAIDNews “Some researchers believe that these lingering immune effects, which are often subtle, may represent the sorts of immune system ‘scars’ that Leitner describes.” bmj.com/content/390/bm…

@NIAIDNews “Dawn Bowdish, Canada research chair in ageing & immunity at McMaster University, says clinical signs are visible. ‘For people who test positive for covid-19, there’s an uptick in antibiotic prescriptions. Covid-19 does have this association, for sure.’” bmj.com/content/390/bm…

@NIAIDNews “@VirusesImmunity says that the clinical picture aligns with what she sees at the cellular level. Iwasaki says that even in patients not admitted to hospital, her lab sees clinically significant reductions in circulating T cells.” bmj.com/content/390/bm…

@NIAIDNews @VirusesImmunity “A Cell study of people with #LongCovid suggests SARS-CoV-2 infection can reprogram bone marrow stem cells, imprinting epigenetic changes that persist for at least a year, skewing some immune cells towards a state of hypersensitivity & inflammation” bmj.com/content/390/bm…

@NIAIDNews @VirusesImmunity “The findings signal a possible novel mechanism for longer term immune changes not strictly limited to populations with #LongCovid.”

@NIAIDNews @VirusesImmunity “There has definitely been a change in the character of the immune response since 2019,” says Tim Henrich, immunologist @UCSF “It’s certainly impacting our immune health, and probably our overall health as well.”bmj.com/content/390/bm…

@NIAIDNews @VirusesImmunity @UCSF “#LongCovid remains a hot topic among the public and researchers and has certainly raised awareness of postviral disease. Yet there persists an awkwardness, even a hostility, when it comes to the idea of SARS-CoV-2 undermining immune health.” bmj.com/content/390/bm…

@NIAIDNews @VirusesImmunity @UCSF “Jeimy thinks that people who are unwilling to consider the possibility of immune damage are perhaps driven by a fear of what those answers might mean”

“Nobody wants to be the one that says, ‘Yes, covid-19 causes disability’ [beyond long covid],” bmj.com/content/390/bm…

@NIAIDNews @VirusesImmunity @UCSF Gasperowicz says that “the burden of proof has flipped: instead of showing that something is safe, we’re asked to prove harm.”

@NIAIDNews @VirusesImmunity @UCSF “Henrich doesn’t see the hypothesis as controversial. ‘We’ve shown immune dysfunction post covid, including signs of exhaustion & inflammation in people without symptoms.. at population level, we are probably living with more inflammation on a day-to-day basis than.. before.’”

@NIAIDNews @VirusesImmunity @UCSF “In some patients the impact of covid-19 is dramatic; in others it’s invisible. @VirusesImmunity and her team have found persistent immune system changes in people who have recovered from covid-19, even without any symptoms.” bmj.com/content/390/bm…

@NIAIDNews @VirusesImmunity @UCSF “There are some subtle differences between healthy controls & convalescent controls.. More subtle things might be happening in that population. And now the entire world is pretty much the convalescent control.” — @VirusesImmunity bmj.com/content/390/bm…