Coronavirus Update 57
March 14th, 2022
Omicron's sibling, the new variant BA.2, does not appear to be doing anything interesting. Current Covid cases remain 90% Omicron BA.1 and the remainder BA.2. Disease remains mild compared to the tough Delta strain for both BA.1 and BA.2. BA.2 is very contagious, but it appears that so many people have been exposed to BA.1 that there is no naive human tissue for BA.2 to take hold in.
Quick Hits -
1) The brain continues to show signs of damage from SARS2 infection. A group in the UK investigated brain changes in 785 UK Biobank participants (aged 51–81).
They imaged each person twice with 401 cases testing positive for SARS-CoV-2 between their two scans. The remainder of subjects were controls. They state: "We identified significant longitudinal effects when comparing the two groups, including: (i) greater reduction ingrey matter thickness and tissue-contrast in the orbitofrontal cortex and parahippocampal gyrus, (ii) greater changes in markers of tissue damage in regions functionally-connected to the primary olfactory cortex, and (iii) greater reduction in global brain size. The infected participants also showed on average larger cognitive decline between the two timepoints. Importantly, these imaging and cognitive longitudinal effects were still seen after excluding the 15 cases who had been hospitalised. These mainly limbic brain imaging results may be the in vivo hallmarks of a degenerative spread of the disease via olfactory pathways, of neuroinflammatory events, or of the loss of sensory input due to anosmia." (Douaud et. al. 2022)
What this study is saying to me is this: susceptible individuals with leaky blood brain barriers will have more SARS2 virus penetrating the brain tissue leading to increased brain volume loss which could and likely will lead to cognitive decline. This is likely to accelerate issues in people predisposed to dementia and other neurodegenerative diseases. The fact that this occurred in people with mild disease leads me to believe that the critical factor here is the brain's permeability. The blood brain barrier is supposed to keep viruses and bacteria out. Why are some people having increased issues here? For that answer we need to understand why the blood brain barrier becomes leaky.
Low oxygen states like a stroke are known to cause leakage of the blood brain barrier, BBB, however this would only account for the damage to the brains of people with advanced disease. It turns out that chronic dietary exposure to glucose and fructose can disrupt the BBB. From a study in Frontiers in Aging and Neuroscience we find these comments: "After 24 weeks, HFF (HFF stands for high fat and fructose diets) fed mice showed significantly deteriorated cognitive function concomitant with substantial neurodegeneration, which both showed significant associations with increased BBB permeability. In addition, the data indicated that the loss of BBB tight junctions was significantly associated with heightened inflammation and leukocyte infiltration. The data collectively suggest that in mice maintained on pro-diabetic diet, the dysfunctional BBB associated to inflammation and leukocyte recruitment precedes the neuro-degeneration and cognitive decline, possibly indicating causal association." (Takechi et. al. 2019)
There are some hypothetical data sets that gluten could disrupt the BBB as it does in the intestine, but this is speculation at this time. Worth an elimination diet challenge if you experience brain fog or cognitive difficulties, especially if you have history of a primary relative with celiac or non celiac gluten sensitivity.
2) All sub variants of Omicron including BA.1 and BA.2 have relatively significant vaccine avoidance ability against mild disease. (Iketani et. al. 2022)
3) In a study looking at vaccine effectiveness against the delta variant we see more reinforcing data that the antibody response to vaccines wanes after the peak at 8 weeks over the next few months leaving T cells as the main defensive reality against Covid. (Wright et. al. 2022) This again leaves us in a world of relying on our natural immune response moving forward against future covid exposure as the reality of boosting every 6 months makes little to no logical sense unless you have serious co-morbid or age related risk. This, of course, assumes that you have had natural disease or a two dose series.
4) In a well written article on the possibilities of vaccinations against covid moving forward, we see many directions and a lot of unknowns. It will take many months to ferret out what the future Covid vaccine recommendations will look like. We will be watching these realities carefully. "ideally, future vaccines should protect, with a single injection, against multiple variants at once. An easy first step would be to combine multiple spikes into one shot—an Omicron-original combo, say, or an Omicron-Delta-original triple threat. Eventually, we might hit upon a universal formula that guards against all variants, including ones we don’t know about yet" (Wu et. al. 2022)
5) If you are interested in the origins theory, Nature has an article looking at three studies pinning the origins on the Wuhan Market and an animal reservoir. (Maxmen 2022)
6) A very needed article reviewing what was done correctly and what was done poorly during the pandemic was published in the Journal BMC Public Health. Some highlights that made me smile: 1) Emphasize education and harm reduction approaches over coercive and punitive measures, 2) Reopen schools now
COVID-19 has caused by far the largest disruption to learning in recent history. As the pandemic has unfolded, there is mounting evidence that the harm of keeping schools closed dwarfs any public health benefits, 3) Avoid lockdowns - the cumulative evidence suggests that “sledge-hammer” lockdown approaches, such as the closing of all non-essential workplaces and schools, should be avoided in favor of more effective, carefully targeted “scalpel” public health strategies. (Halperin et. al. 2021)
7) Vaccine effectiveness with an mRNA vaccine had limited effect against omicron as a 2 doses series when looking at the prevention of symptomatic disease. It worked fantastically against severe disease and death from other recent studies. The booster dose added a layer of benefit against symptomatic disease but that benefit waned quickly. After 10 weeks, the boosters rapidly lose benefit down to 50% range protection against getting symptoms when infected. The booster dose raised symptomatic disease prevention benefits to the 65-70% range initially. (Andrews et. al. 2022)
My take remains the same, booster doses remain a great idea for the elderly, over 65, and all individuals with risk factors.