Transmission
In this small study of Italian health-care workers who were tested regularly, all of the people who tested positive but were asymptomatic tested negative the very next day. The mean time for the symptomatic patients to test negative was 11 days.
Pathology
This preprint says they found SARS-CoV-2 antibodies in the cerebrospinal fluid of two out of the three teens they studied who had neurological symptoms after COVID-19 infection. Those two also had antibodies to their own neurons!
Long COVID
This preprint says that Long COVID symptoms are more common in adults than children (look at the right-hand graph below, not the left) for all symptoms, but infected kids still had a lot of symptoms compared to non-infected controls.
Vaccines
This article says that Moderna says that it got good results with a half-dose in kids 6-11. I can’t tell if they did a randomized control trial vs. placebo or not — the articles I can find just talk about antibody levels in test tubes.
This article reports that a big study in the UK found that about 3.8 people per million who get the AZ vaccine develop Guillain-Barré syndrome. However, they also say that 14.5 people per million who get a COVID-19 infection develop Guillain-Barré syndrome.
This is a somewhat opaque highly technical workshop summary on beneficial secondary vaccine effects (SVEs), which I’ve talked about in the context of live attenuated virus vaccines. Alas, the article does not have a nice clear “this is how a vaccine against X also gives protection against Y” narrative, more of a “these are the puzzle pieces we know about right now. What I found most interesting was its observation that, basically, we have no structures — neither regulatory nor economic — in place for evaluating/approving/giving extra consideration to a vaccine based on its beneficial secondary side-effects.
It sounds like the body reprograms various parts of the immune system to be more effective virus fighters. The thing that puzzled me about that was, “why would you ever not have your immune system trained for more effective virus fighting?” One answer I thought of was that maybe it takes more energy to be more effective at fighting viruses, but it sounds like some of the changes are not in doing something, but setting things up so that it’s faster to Do The Thing when needed. The closest analogy I could come up with is like having evacuation plans written down somewhere: you don’t need to do an evacuation all the time, but you don’t want to have to think about it when The Bad Thing happens.
So why, then, would you not have the immune system ready to go fight viruses? Well, there was a paragraph in this paper which reported on work which found that influenza vaccine gave improved protection against viruses but decreased protection against bacteria. Ohhhhh! Continuing the analogy, following the evacuation plan for landslides might be exactly the wrong thing to do when you need to evacuate for a tsunami.
There was also a fleeting mention of the possibility of the SVEs being linked to the gut biome. We humans are learning that the gut biome has many surprising and significant effects on human health, so maybe it is involved in SVEs also?
Testing
This article says that Air Canada is offering its passengers a self-test kit that they can take with them for their pre-return test. Somehow it’s a PCR test in a box, I’m not sure how it works, but it’s an awesome idea!
Variants
This report says that Delta+ (also called AY.4.2 and VUI21-Oct-01) is slightly more contagious than Delta, but only slightly.
| Delta | Delta+ | |
| secondary attack rate, household | 11.1% | 12.4% |
| secondary attack rate, non-household | 4.0% | 4.4% |
Recommended Reading
This article talks about the dry runs which vax makers are doing to prepare them to quickly switch strains, if they need to.
This piece on the declining role of public health over the past decades is worth a read. I have a real sense of deja vu, like someone else wrote almost the same article? Maybe because I read the book Premonition?