Coronavirus Pandemic (COVID-19) (SARS-CoV-2) [2020]

This isn't the political/ethical discussion.


Cases definitely appear to be heading down in England. Lots of people with heavy colds and not a huge amount of other viruses around it seems, so cases probably higher than being measured. Well, certainly higher than being measured as they aren't measuring much! A correlation between number of cases and reduction in tests makes it hard to gauge reality, although the numbers in the graph and plot don't coincide with a 40% change. the wiggle in testing counts around September explains the apparent short wave in cases at that time - peak and trough were caused by sampling, not viral spread.


PCR +ve is dropping

Is there any approximate measure that'll actual give an indicator of broad population infection rate? I don't think the ONS is still tracking and reporting their estimates.
I mean from something people are actually providing! Metrics like 'cases' are reported but not indicative of anything. 'Hospitalisations' are at least being tested against in the UK, I believe, but how indicative is that of the general population?
Researchers at the University of Pennsylvania have found a possible pathway for some brain fog symptoms afflicting Long Covid patients. The theory is that viral persistence reduces serotonin levels and serotonin is produced in the gut and the brain connects to the gastrointestinal tract through the vagus nerve which may be affecting hippocampus activity.

"In about 30% of patients, we could find viral RNA in their gastrointestinal tract, so we took this and tried to model it in mice," says Levy, an assistant professor of microbiology at the University of Pennsylvania.

Those experiments revealed that a chronic viral infection (they used lymphocytic choriomeningitis virus as a stand-in for SARS-CoV-2) also led to reductions in serotonin and that the body's own immune response seemed to be the culprit.

This led to further experiments focused on a cytokine, called type 1 interferon, revealing that this signaling protein was driving inflammation and interfering with serotonin levels in the bloodstream in several ways.

The gut produces 90% of serotonin in the body. The amino acid tryptophan is critical to this task — it's a precursor to serotonin and gets absorbed in the gastrointestinal tract from the food we eat. Except, this inflammatory response in the gut actually impaired the absorption of tryptophan.

"If there's less tryptophan, there's less serotonin production," says Thaiss. On top of that, these cytokines also lead to clotting of blood platelets — which store serotonin — further reducing the amount of serotonin in circulation.

The brain connection

Here, the detective work moved away from the gut to the vagus nerve, which essentially acts like the brain's monitoring system of the body and connects to the gastrointestinal tract and many other organs.

Levy says they found this reduction in serotonin impairs communication between the vagus nerve and the brain, which then reduces some activity in a region of the brain known as the hippocampus.

What's promising, though, is that the cognitive symptoms the Penn researchers documented in mice could be reversed.
"We can make the animals remember perfectly again by just reactivating their vagus nerve or by restoring their serotonin signaling," says Thaiss, referring to a cognitive behavioral test they performed on their mouse models of long COVID.

Researchers don't believe there is a sole cause for LC or one mechanism to explain LC symptoms. But this brain-GI connection may explain some of the brain fog symptoms as well as point to possible treatments.

Read in NPR:
This wave is definitely on the way out:

Testing has remained relatively constant and doesn't account for the downturn. That means the latest wave is over a 6 month cadence versus the 3 months of previous waves. Actual numbers of infection are likely comparable to other waves - these lower numbers this Autumn come from lower testing. PCR positivity is much higher for this wave than previous, so lots of unreported cases.

That said, recorded health impacts correlate quite closely.


Here the line is cases, undercounted; the blue bars are deaths and the orange patients admitted to hospital. Unless these are being counted lower as well but that certainly can't be the case with recorded deaths.

From the beginning of this year, the shape of COVID19 has clearly changed from 3 month peaks on a choppy ocean to 6 month swells of diminishing magnitude. I think that's pretty hopeful for the long-term assimilation of SARS-CoV-2 into the background microbial fauna.

Impact of Long Covid and what recovery is like is pretty much an unknown at this point. I don't know who's tracking it and, without a clear market to profit off, I doubt it's high priority for anyone even though it's invaluable in understanding human immune responses to novel viruses and what we could face with other pandemics.
Where are you getting the idea of another lockdown from? Covid's impact is diminishing over time. The latest wave has come and largely gone without need for extreme measures. Or any measures, almost. Vaccines were offered to over 65s with about a 65% uptake AFAICS.
I don't think there have been any lockdowns since last year. China was one of the strongest stalwarts of Zero Covid and they've relinquished, as did Australia. Everyone's just accepted it as the costs to try to control the pandemic clearly outweigh the losses of not trying and just relying on acquired immunities. I don't think any country could survive the economics of weeks-long lockdowns again!
Then again it is unfortunate there seems to be so little middle ground between "lockdown may be required" and "I don't care". Right now, healthcare is getting hit hard by the extra load from covid again in Finland. Mainly it is just the resources still being chronically thin so anything unplanned is a big problem. But there is not really any effort on personal level into distancing at the moment. At minimum, people could just put a mask on when meeting people in case of any feeling of unwell, or in case of sickness in the family. Staying out of your workplace when feeling sick is mostly respected, but not as strictly as a while ago.

Just recovering myself from this year's bout of covid...