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. 


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. 


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. 


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. 

51 thoughts on “How likely is Covid reinfection?

  1. Nationalism will destroy the battle to kill covid! Like my analogy of the farmers fields: If a farmer only sprays every other row of crops for a pest infestation, the pests in those treated rows will die and the untreated rows will still have the pests. When the treating stops the untreated rows will infect the treated rows again! Ask a farmer or gardener if they would only treat every other row and they would say you are daft! That is what is happening with the world effort to end covid. There are no walls around each country, (except for the 84 miles of wall that Trump built), and even if there were, people could pass through them either through gates or ladders. Since I am a US citizen living outside of the US this is easy to realize. Brittan and the US along with many affluent countries suffer from extreme nationalism, and it will end up biting them in the arss. We all live on the planet Earth but many do not think this way!

    Liked by 1 person

    • I did one Covid test and I’m reasonably sure I didn’t get the swab anywhere close to the area it was supposed to reach, but the only instructions I can remember were to stick it up my nose. I did find my nose.

      I wonder if there’s been a time in the history of the English language when we’ve used the word swab even half as often.

      Liked by 1 person

  2. I enjoy your updates on current affairs from across the pond, Ellen. There has been quite a few inconsistencies about COVID testing, vaccines and vaccinations….I guess we are all learning as we go along. We are doing alright here in Australia with COVID but we’ve had people tested negative a few times before testing positive in a short span of time.

    This all seems like we are in one big experiment. But practicing social distancing, good hygiene and no travel for now is the way to go.

    Liked by 1 person

    • Agreed. The countries that have been most cautious have also been the most successful, and I’d be shocked if they had any regrets. If we could get a quick, reliable test that’s idiot-proof, it would be wonderful, and maybe we will at some point. The science has been moving so fast, and the scientists have been so impressive.


      • Your post also got me thinking. We all come in different shapes and sizes, and surely the insides of us have different measurements. Overall the test instructions are inconsistent delivered and applied in some ways. It would be great if there was also more talk and research done about finding a possible cure to all of this.

        Liked by 1 person

        • There’s actually a lot being done, but It’s hard for me, at least, to write about. Some of it is promising but only in preliminary tests. Some of it decreases people’s time on, say, a ventilator or the likelihood of ending up there. None of it is yet a cure. For most of us–non-specialists; non-doctors–it doesn’t sound like progress, because we all want that full-blast cure. It is progress, but it’s slow progress. Work is being done.


  3. Nice summary and updates, especially the last part, Ellen! I already had my first vaccine shot, but cannot put the guard down, especially due to the virus mutations. About the cases of COVID infection, some patients did not have strong symptoms until almost two weeks. There are many things we need continue to learn about this COVID!

    Liked by 1 person

    • So very many. And yes, I have to keep reminding myself about not letting our guard down. So far, what I’ve read says that the immunity to the new variants isn’t bad, but even so, it’s not just about us. We don’t know that we–those of us who are vaccinated–can’t transmit the disease. So we still have other people to think about.

      Liked by 1 person

    • They’d have to go back to the historical system where people brought their own containers. Even if they gave the stuff away, they’d save someone money, because it wouldn’t need to be trucked around. And they’d buy an immense amount of goodwill. They could even give it away but accept donations.

      Okay, I’m completely absorbed by the idea. Let’s have the beer bank accept donations for the food bank. Everyone wins.

      Liked by 1 person

  4. Seems like the beer would end up in the sewage system anyway, and if it was just poured down the drains to begin with it would make it a little less – um- in need of purification.
    I tried to imagine those 3000 people in my kitchen, but got hung up on ordering pizzas and whether anyone else would accede to anchovies.
    There was just a news bit today about how having caught Covid would not necessarily immunize you to a mutated form. Even though it’s been around for a year, it seems no one is yet able to draw an accurate conclusion, which is somewhat discouraging.

    Liked by 1 person

    • It (that’s Covid) is always running just ahead of the scientists. The implications of what I’m reading seem to be that vaccination offers a wider spectrum of immunity than having caught it before. But speaking of implications, I overlooked the implications of all those people in your kitchen in the middle of a pandemic. What was I thinking? If only one of them has an asymptomatic case, I’ll be responsible for a superspreader event. I’m mortified.

      Liked by 1 person

  5. Hello, Ellen–your blog is something I read as soon as it appears and it always is entertaining AND pertinent! Also comments by your other readers are quite informative; viz. that #45 only got 84 miles of that wall built. Very cheering. I also have heard that states and non-ICE agencies like wildlife management are disassembling some of it and converting some to low-cost housing construction supplies–I hope so. The COVID situation here is almost as bad as in the UK, though the rates of transmission and deaths have dipped quite a bit and so have the rates of colds, flu and other common illnesses which ought to be enough to convince the anti-vaccers and anti-mask that we are doing the right thing with distancing, lockdowns, masks, etc. Thanks again, hope you can clear Boris off the decks as we did with the orange menace. Cheers!

    Liked by 1 person

    • My impression, although I haven’t seen comparisons lately, is that the Covid situation’s worse in the states, although the epidemic’s dipping at the moment. Ii saw an interesting article, though, comparing the way flu and Covid spread, which I really do need to write something about. Stay tuned. (You probably have to be over a certain, and considerable, age to even know what that means.)

      I’m afraid we’re stuck with Johnson for a while. Sigh. The only consolation is that if we replace him too early, we might manage to get someone even worse. (Yes, it is possible.)


  6. 189 in some circles would be referred to as an “epidemic sample”. Small. Large margin of error. 189 people in your kitchen would be epidemic.
    Now 3,000 (in your kitchen) would be a pandemic sample.
    (See Hawley et al. in a previous publication for further reference…)

    Liked by 1 person

  7. Thanks for the global round up on covid. I was a bit shocked by.. “. 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….” , this bit of information.

    It made me think of those taking the vaccine, could the same thing happen there?

    Mum had her vaccine a week ago and initially no side effects, but then she went all weird on wednesday through to friday. It was stressing as mum has a heart condition, pacemaker and other stuff, we couldn’t figure out what it could be. But I think it the vaccine ( Oxford one she took).

    Liked by 1 person

    • That was why they made a point to include older people in the vaccine trials: We don’t (to generalize) generate as enthusiastic an immune response as younger people. I’m out of my depth on why vaccines are presumed to generate a more reliable immune response than the disease itself, but that does seem to be what they’re saying.

      Is your mother okay now?


  8. Initially, after myself and my whole office was sick, we did not wear masks. We didn’t have clients in so we didn’t worry about it at all. The office itself wasn’t well for months – it was very sick, I’m certain. Yet we never hesitated to pick up someone else’s phone and push buttons on equipment. When ‘They’ started reporting possible reinfection, we all started wearing masks, placed sanitizer and wipes on ‘centers’, hung a sign warning people no entrance without masks, and I became the official czar of wiping and spraying ‘centers’. I lost a month, one of my colleagues lost almost two months. Her youngest child was hospitalized. Preventing is our thing, because none of us can afford to lose time like that. Not pay, you understand — TIME.
    None of us were tested while we were sick and only some of us had antibodies after, didn’t have them, had them, didn’t have them — there was no logical-chronological correlation which filled us with doubt and concern over the testing.
    I have never had beer in my kettle or my tub, neither have I contributed to the wooziness of trout, but the idea made me smile :)

    Liked by 1 person

    • My kettle and tub are also innocent of all alcoholic content. I probably should’ve mentioned that.

      Interesting story about the office. I expect some epidemiologist would have a wonderful time trying to untangle what actually happened there. But the child being hospitalized–I’ve read about the rare cases where kids become seriously, seriously ill with it but this is the first time I’ve known anyone close to a case of it actually happening. So many people take this thing so lightly–they’re young, they’re not the bullseye in the statistical target, so they think they’ll be fine, but they can’t know that. And they can’t know how the people around them will be. I’m glad you’re the prevention czar. We’ve all got to get through this alive and well.

      Liked by 1 person

  9. When I lived in an unspecified town in the West Atlantic Islands, there was an off-license we used to call the “gone offy” because they would sell past-their-sell-by-date beers on the cheap. Pretty eclectic beers and ales too-it was the first time I ever drank Old Speckled Hen, and I’ll never forget the look on the gentleman’s face when I asked him to pass me out a bottle of Waggle Dance from the fridge.

    Liked by 1 person

    • Great name for the off-license–and I can’t imagine the taste was any different or the alcoholic content any lower. They even put a date on salt, which is a preservative. How silly can we get?

      I used to work for an arts organization that could, collectively, talk itself out of any joke that anyone proposed. It was heartbreaking. I think all the jokes we rejected must’ve gone to work for craft beer companies in the naming departments.

      Liked by 1 person

    • I sure don’t. I know that people who’ve had the test done to them, as opposed to doing it themselves, say it’s uncomfortable. When I did it myself, I stopped short of pain, although I was mildly uncomfortable. I suspect I was nowhere close to where I was supposed to be, but who’d know?

      Liked by 1 person

Talk to me

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.