2021-05-05 General

Vaccines

Pfizer has been approved down to age 12, yay!!


Moderna has been doing a clinical trial with a booster made to mimic the spike proteins of B.1.351 instead of COVID Classic, and their press release says it works better against B.1.351 and P.1 than a third shot of Moderna Classic. (Note: it “works better” in test tubes. Presumably there weren’t enough people who got sick to calculate efficacy that way.)


The US is backing a patent waiver on COVID vaccines. I’m not ideologically against patent waivers, I just don’t think they will help much in getting vax out to the people. The time/cost of building a factory and access to raw materials and knowhow are much, much bigger barriers (as this article also posits). There is also going to be an absolute flood of vaccine in 2022, even without IP waivers.


The Pfizer vaccine does not harm sperm. You can sleep easily now.

Variants

The US CDC has downgraded B.1.526 (one of the “New York” variants), saying basically that it’s not a concern, yay!

Disease

This paper says that one difference between COVID survivors and uh non-survivors is the speed at which they produce neutralizing antibodies. It sounds like people with fatal COVID just can’t pump out the antibodies fast enough. 🙁

Airborne v. Droplets

There has been a lot of frustration about whether COVID-19 is airborne or not. LOTS of bits have been devoted to this argument. The way I personally think about it is that while long-distance spread CAN happen, usually it DOES not. 

I believe that what epidemiologists call “airborne” is a little different than what lay people call airborne (i.e. “transmitted through the air”).  In a press conference, Dr. H said something about how “airborne” meant “through ducts and around corners”.

NOBODY disputes that the particles travel through the air.  The question is how far do they travel, and how long do the particles hang around?  Measles hangs around suspended in the air for so long and is so transmissible that you can catch it by walking through a room where someone with measles was a few hours earlier.

EVERYBODY agrees that big droplets spread COVID-19. EVERYBODY agrees that COVID-19 particles go through the air. Those are not in dispute.

After that, it gets grey.  I have a friend who I swear thinks that the virus emerges from mouths like swarms of angry mosquitos and makes a beeline for uninfected people.  That ain’t how it works.  (If it were, we would ALL have gotten sick.)  Dr. Henry says that plexiglass partitions have proven effective, and those certainly wouldn’t be effective against the angry-mosquitos model.  (She could be wrong, I suppose, but I sure hope that she and her team are more competent than that.)

There’s also nothing magic about 2m. (Particles containing viriuses don’t do a 90° turn towards the ground at 2m.) Some particles will travel farther, some won’t travel as far.  It depends on how loudly the person is talking, the air currents, the air temperature,  the air density, and some other factor (which scientists haven’t figured out yet) about the person transmitting (how loudly they talk?  how much vibrato their voice have?).

The receiving person’s immune system also affects whether a “successful” transmission occurred.  Like maybe Fred speaking normally results in 49N virus particles making it to someone standing 2m away, and your immune system today can handle 60N but mine can only handle 40N today. Maybe I need to be 3m away to be safe.

All this gives a huge number of shades of grey, and most humans are uncomfortable with grey.  Sorry.

HOWEVER, as a practical matter, contact tracers have to use some number, some cutoff to decide which contacts need to be followed up on and which do not. Otherwise, their job becomes intractable. 2 metres is a distance which is usually safe for most people, so the contact tracers use that.

There are some well-documented cases of transmission farther than 2m and/or through ducts. Almost the cases of long-distance spread which I can think of are some combination of singing, vents blowing air, and cold temperatures (e.g. meatpacking plants). 

There are some particular cases in a restaurant and a bar of people getting infected by people who were upstream of them in a place with noticeable airflow. I don’t know what the temperature were, but the vents were called air conditioning ducts, and most AC that I’m familiar with blows air which is way too freaking cold. Also, note that in both the cases I linked to, there were people in the establishment who were as close but not in the airstream who did not get infected.

One exception to singing/blowing/cold is the Diamond Princess: COVID-19 appears to have travelled through the ducts there.  I don’t now how cold that air was, but I suspect that old people cooped up in their rooms 24/7 might be more susceptible than the average person/situation.

Another exception is a case in New Zealand where infected person A opened a door, breathed for 50 seconds, closed their door, person B opened a door ten feet away, and person B got infected. 

HOWEVER, the two cases above are anomalous cases, written up because they are odd.  We don’t have writeups for all the times transmission did not occur around corners or through ducts.  I suspect that if it was common for transmission to happen around corners and through ducts, we would all be sick by now.

As I said, I think it CAN happen but usually DOES not happen.  Sort of like “Can big airliners crash?”  Yes, of course they can — we’ve all heard about it — but usually they don’t.  They just don’t write articles about the millions of times they don’t crash. 

NACI

The National Advisory Council on Immunizations gave some very confusing guidance yesterday. They said that the mRNA vaccines were preferred, and that Canadians should weigh the risks before they decide which one to receive. NACI’s chair went on to say “If, for instance, my sister got the AstraZeneca vaccine and died of a thrombosis when I know it could have been prevented and that she is not in a high risk area, I’m not sure I could live with it.”

Well. This did not go over well. People were confused at the change in message after Everybody Else saying, “take the first one you are offered”, and angry that NACI abdicated the careful thinking about the vaccine to the reciepients.

This exchange by Dan Mazur and Thomas Levi unfolded on social media:

Mazur: The wooden lifeboats are the preferred lifeboats. Just imagine if your sister used the inflatable lifeboat and it sunk. How could you live with it? We’re not necessarily saying don’t use the inflatable lifeboat, all we’re saying is to understand the risks and make an informed decision. Also, all the wooden lifeboats are full-up, so good luck.

Furthermore, it has come to our attention that some people are clinging to life preservers or floating bits of wood. You should know that this is extremely suboptimal. It is very cold and there are sharks, so you should have gotten into the wooden lifeboats before they were full.

Levi: If you’re currently in a part of the boat that is mostly above water, you may want to wait for a wooden lifeboat, or even better, a metal one which was ordered but hasn’t arrived yet. If you’re mostly under water, the risks of an inflatable boat may make sense for you. Also, all lifeboats are effective at preventing drowning. They are all safe. I wouldn’t use that inflatable one though, but you could. It’s safe. If you want it.

Wooden lifeboats have always been the preferred lifeboats, except during that brief period where we suggested that people who worked on the boat that was sinking should take inflatable lifeboats, mostly to make room for the more important people to get in the wooden ones.

In addition, consider the relative risk, if you’re mostly above water at this current time, you may want to wait for a preferred lifeboat to row to your section of the boat. Do note however, that the boat is continuing to break apart, so though you’ve taken all precautions and moved to the part of the boat currently most above water, this could change at any moment. Consider calculating the relative risk.

We repeat, all lifeboats are safe. Wooden lifeboats are preferred. Inflatable lifeboats are also safe. If you’re in such a rush to not drown, take an inflatable boat. Which is not safe. But all boats are safe and prevent drowning. Just not the inflatable ones.

Everyone got it?

Also, if my sister wasn’t currently drowning, got in an inflatable boat, and a lucky shark bit through her boat and it sank, and then she got eaten by that shark when she could have waited for a wooden boat, I’d never be able to forgive myself.

Mazur: To summarize, in order of preference:

  1. Get in a wooden lifeboat if one is available
  2. Pay a number of the stronger swimmers to form a raft that you can sit on to be safe from the sharks and the cold until the metal lifeboats arrive
  3. If absolutely necessary, consider the inflatable lifeboats

Levi: But all boats are safe. In addition, the Coast Guard has recently provided some single use rafts. Unfortunately these rafts were manufactured at a facility that recently mixed them up with life preservers, so we have decided to delay parachuting these in till we can test all of the rafts.

And to sum up: We recommend waiting for the jet packs.

(Mazur’s portion appears under a Creative Commons By 3.0 license.)

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