How likely is Covid reinfection?

A small study–it turns out that 3,000 people is a small group as long as they’re not all in your kitchen–hints that 10% of the people who’ve had Covid can get reinfected. 

Possibly. 

Or, of course, possibly not. First, the study (like so many in these scientifically frantic times) hasn’t been peer reviewed, so it doesn’t have the Good Housekeeping Seal of Approval. Second, the reason 3,000 people is a small group is that only 189 of them turned out to have previously had Covid. So that would mean–what?–18.9 of them got it a second time. 

Now we stir vigorously and compare that to 48% of the previously uninfected group who picked up Covid, meaning that having had the disease leaves you with a fifth the risk of getting it again compared to someone who’s never had it. Or so the study says. My brain glazed over just typing that. If there’s anything odd about the numbers, you can blame my brain, not me.

These were young people–probably in their late teens, maybe early twenties–and recent recruits to the US Marines. Interestingly, all the reinfections were from the same variant of the virus as their original infections, not the new strains that are circulating, so we don’t get to blame the reinfections of the virus’s tendency to mutate. 

All the recruits had mild symptoms, but the length of infection and risk of having symptoms was the same for both the previously infected and the previously uninfected. It may be significant that the previously infected people had lower levels of antibodies, suggesting that some people don’t generate antibodies–or don’t generate them as enthusiastically.

Irrelevant photo: A hellebore, a.k.a., a Christmas rose.

The moral of this story is that masks, distance, and vaccination still matter, even if you’ve had the damned thing. 

The whole tale ends with a warning: It’s a small study and very preliminary, so take it with a grain of salt. Why did I bother you with it, then? Because it’s interesting. And I like the idea of three thousand people in your kitchen.

Although not in mine.

 

Tests, studies, and work-in-progress

A study in Aberdeen shows that the single strongest influence on a country’s death rate from Covid during the first wave of the pandemic was international travel. The more travelers came into the country, the more deaths it had. 

And the moral of that tale is obvious and tells us what we should’ve done. There’ll be arguments, though, about how what we should be doing now. Is it too late for limiting or stopping travel to work? Discuss. 

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In an early trial, an antibody cocktail blocked 100% of symptomatic Covid cases in people who’d been exposed to the disease. On top of that, their asymptomatic infections lasted a shorter time and their viral load–the number of teeny tiny viruses attending the party inside each infected person–was significantly lower than in the control group.

And if that isn’t impressive enough, the viruses kept the music levels significantly lower at the parties and no one called the cops on any of them. 

This isn’t a vaccine, and it doesn’t prevent a later infection. It’s the first treatment to offer protection to people who are known to have been exposed–say an unvaccinated person caring for someone who has Covid. 

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Britain’s setting up a test of mix-and-match vaccines. This won’t work like those candy displays that take up a whole wall and let you pick 100 grams ( or 3.5274 ounces, give or take a few decimal places) of mixed jelly beans and 100 of (shudder) licorice, but it’s close enough. Participants will get one dose of the Pfizer vaccine and one dose of the AstraZeneca, although not necessarily in that order and they don’t get to pick which way it goes.

On the other hand, they can be sure that they won’t end up with licorice, and I don’t care what they say, it’s for their own good.

The two vaccines are very different, and use very different–well, let’s call them platforms. Mixing the two inside one human is sort of like combining  a horse race with a concert. It’s hard to know what’ll happen. One vaccine comes riding in on a small bit of genetic code. The other is played by a string quartet on a deactivated cold virus.

Okay, that metaphor went wrong. I’d take it out but it’s so wrong that I’d miss it. We’ll just move on and pretend this is a day like any other, okay? Just a perfectly normal day.

The trial hopes to recruit 800 volunteers, will run for 13 months, and will also play around with the length of time between the doses to see what effect that has. 

Volunteers have to be over 50, unvaccinated, and live in a few specific areas in Britain. If you’re interested, you can sign up at the NHS Covid vaccine signup site. It’s not specific to this one trial, so you may have to wander around a bit on your own. If you hear a string quartet, you’re in the right place. If you smell licorice, run.

 

How not to do Covid testing

Canadian otolaryngologists have lined up the Covid test instructions used in all the Canadian provinces and compared them, and they turned out to be wildly inconsistent. In fact, I’d begun to wonder if the size–and possibly shape–of Canadian heads depends on geography.

In the Northwest Territories, Nunavut, Ontario, Saskatchewan, Prince Edward Island, and Alberta, people are told to insert the test swab to a depth of four centimeters, or half the distance from nostril to ear. 

I have to interrupt here, because I was confused about that “distance from nostril to ear.” Are they measuring that on the outside of the head? Or is it as the crow flies, assuming a small crow that could fly through bone and whatever else Canadians keep inside their heads? And is the nostril just that hole at the tip of the nose or the whole passage that rises toward the arched eyebrows that signal confusion? If it’s the second, what part of the nostril are we talking abou?

I could go on, but I’ve probably introduced you to enough of my befuddlement. Whatever Canadians keep inside their heads, I’m telling you, it’s strange inside of mine. 

Whatever the instructions mean, the article told me that four centimeters would take the swab to the mid-nasal cavity, not the nasopharynx, which is where it’s supposed to go to find the viral gold at the end of the Covid rainbow. So done as prescribed, the test will kick up a lot of false negatives.

In British Columbia and Manitoba, people are told to get the swab seven centimeters up the nose, which would take it to the posterior nasal cavity but still not to the nasopharynx. Again, false negatives.

In Nova Scotia and Newfoundland, the article I stole this from abandoned centiwhosits and just said it was two-thirds of the distance from nostril to ear, which would take it all the way to the nasopharynx. Yay! Those provinces get the viral gold and we’ll award them some jelly beans to go with it! 

We’ll give some licorice to New Brunswick and Yukon, which tell people to insert the swab from nostril to the external ear canal. That would take the swab to the nasopharynx, so they do get the viral gold, but it all sounds like the swab has to make a 90-degree turn inside your head, pierce your eardrum, and emerge triumphant from your ear. 

Licorice. Sorry.

I’m reasonably sure I misunderstood something in there, but the otolaryngologists think they could maybe improve the instructions if they got involved. I’m inclined to think they could.

 

Vaccine nationalism

Remember Covax? It’s the international plan to ensure that the world’s richest countries don’t suck up all the Covid vaccines, leaving the people of 145 other countries to (a) suffer and die and (b, in case high-minded arguments aren’t enough to move enough people and nations) become a pool in which new variants of the virus will be created before turning around to re-infect the richest countries, which will have been vaccinated but only against earlier variants. 

Was that last sentence long enough for you?

Okay, in case you didn’t remember Covax, you’ve now been introduced and you didn’t have to admit that you’d forgotten its face. Hello, Covax. Glad to meet you. How’re you doing?

Not so well, as it turns out. High income countries have reserved 60% of the vaccine supplies that have been ordered so far. That 60% will go to just 16% of the world’s population.

The International Chamber of Commerce figures that if developing countries don’t get the vaccine, it’ll end up costing rich countries $4.5 trillion. Trillion. That’s 4.5 with so many zeroes after it that I went comatose.

Compare that to Covax’s long-term cost, which is $26 billion. So far, it’s raised $6 billion and needs another $2 billion to fund its initial stage. That’s 1% of Jeff Bezos’s net worth. 

If you find a stray billion or so behind the couch cushions–yours or his–do get in touch. 

Given what will happen to the rich countries’ economies if they only look to their own populations, the article in the Atlantic that I stole these numbers from figures that if the rich countries fund the project fully they’ll get a 166-fold return on their investment. 

 

Beer, Britain, and lockdown

With lockdowns keeping Britain sober–or more probably drunk behind their own closed doors–pubs have had to throw away an estimated 87 million pints of beer since the start of the pandemic. If they’d been able to sell it, that would’ve put £331 million in their pockets.

When beer in barrels isn’t sold before its best-before date, it goes back to the breweries to be–

Um, I’m not sure what the breweries do with it. I know they don’t set it on fire. Give a pint or two to the local stray dogs and drunks, then pour the rest into the river, leaving the trout wondering why they’re so woozy? 

Well, it just so happens that I asked Lord Google, who referred me to the Morning Advertiser, which told me that it gets poured it down the drain. Why does it have to go back to the brewery to go down the drain? Can’t the pub do that? The M. A. was talking about pub drains, not brewery drains, and about water companies wanting to charge them for adding huge amounts of beer to the sewage system.

So we’ve got some conflicting information, but it’s not our topic, so let’s just set it aside and talk about how long beer stays best-before: Pasteurized beers keep for three to four months after they reach the pubs and unpasteurized ones keep for six to nine weeks. 

After that, the dogs outside the breweries start wagging their tails.

How much beer is 87 million pints? It would fill 20 Olympic-size swimming pools, 33 million kettles (standard size, please, because it’s important to get this right), or 495,000 bathtubs. 

The bathtubs, though, aren’t a reliable measure, because they have to be filled to “the usual level required for a bather,” which is worryingly vague. We all have our standards, and I have never yet let a statistician or a beer brewer into the tub with me–at least not knowingly; people do lie about these things–so they’re guessing at how high I fill the tub. They’re probably guessing about  your tub too. 

I’m less selective about who gets near my tea kettle. I don’t know about you, but I’m inclined to trust them on that.