How long does Covid immunity last?

This is still up for grabs, but the Covid vaccines–or some of them anyway–may not need yearly booster shots. Or may only need them every few years. 

To understand this, you have to know that the body’s immune system is a hierarchy.

Well, no, it isn’t really, but it’s a workable way to think of it. At the bottom are the antibodies, which swarm in and kill things, and they get most of the press because they fly flags and have marching bands and we notice that. But they don’t have long memories, so we have to worry: If the same enemy–in this case, Covid–comes back, will they recognize it?

Above the antibodies, though, are other bits of the immune system–plasma cells, memory B cells, memory T cells–and they have longer memories and they’re the bits of the system that crank up the antibodies, show them pictures, say, “That’s what the enemy looks like,” and send them out to kill and die.

It’s not a nice world out there. Or in here, on the inside of our bodies. 

Irrelevant photo: a poppy

Immunologists also have long memories, and they’ve been busy working out how long Covid immunity lasts, both after an infection and after vaccination. The answer depends on understanding the actions and interactions of all those different ranks. 

They’d also, I’m sure, hate my explanation of how this works.

The unpredictable element in all this is the rise of Covid variants. So far, they haven’t outrun our immune systems or the vaccines, but some variants do slow them down. 

The primary sign that a variant’s gotten faster than the vaccines will be if a whole lot of vaccinated people suddenly come down with Covid. 

I know, that’s not the way we’d like to get the news–a telegram would be better–but like I said, it’s not a nice world out there.

Assorted trials are underway, testing booster shots and testing the effect of mixing vaccines. It will be up to individual countries to decide if boosters are needed, but work’s underway in case they do.

*

In the meantime, studies from northern Italy, which was the first part of Europe to be hit hard by Covid, say that immunity lasts at least a year and may last longer, only there hasn’t been time yet to find out. Reinfection is rare. But the experts are still urging people who had the disease to get vaccinated. It will boost their protection and make them more likely to resist variants. 

As for the vaccines, they’re protective for at least a year and possibly for a lifetime. 

Michel Nussenzweig, an immunologist at Rockefeller University, said, “People who were infected and get vaccinated really have a terrific response, a terrific set of antibodies, because they continue to evolve their antibodies,” Nussenzweig told The Times. “I expect that they will last for a long time.”

 

So that’s the good news out of the way. Let’s have some bad news for dessert.

The Delta variant (no I don’t know why we capitalize Delta; I do it because the papers do) is now the dominant U.K. variant. As many as 75% of the new U.K. cases may be Deltas. That’s the variant formerly known at the Indian variant, or B.1.617.2, but India changed its name to Delta and the variant’s followed along behind.

No, you really shouldn’t believe everything I say.

Annoying as the name changes are, it’s a good thing, given the human propensity for stupidity in the form of blaming other countries and peoples whatever goes wrong, that they’ve stopped naming variants after countries. Unfortunately, it’ll take some of us a while to catch up. 

So. Delta variant. Dominant strain in U.K. It seems to carry a higher risk of hospitalization (2.61 times higher) than the Alpha variant, formerly known as the Kent or British (or U.K, or English) variant. 

Sorting out the U.K.’s name is a constant problem, so I look forward to the time when the country changes its name to Alpha. It’ll be much simpler to write about. And since Alpha’s the first letter of the Greek alphabet, it should keep the nationalists happy.

Yay, Covid! We got there first!

Where were we?

The number of hospitalized Covid patients in Britain is small right now, as are the number of cases, but the number of cases is growing slowly. The worry is that this is the start of a trend.

Working against that is vaccination: 73% of the Delta cases are in people who haven’t been vaccinated. Two doses are a good protection, although not as good as against the Alpha variant. One does, though, is 17% less effective against the Delta variant. 

In the meantime, schools and colleges (if you’re American, British colleges stand somewhere between American high schools and American colleges) in England are responsible for a good deal of the spread

Why them? Partly because they collect a whole bunch of people who aren’t priorities for the vaccination programs–or even eligible for vaccines–and jam them together. Preferably in badly ventilated rooms where they nod off gently while trying to absorb important information. And also because the government lifted its mask mandate for secondary schools. That did affect primary school students because they were always considered too young to locate their noses and mouths. Adults are, demonstrably, still having trouble with that. 

Why did it lift the mandate? I’m still struggling with that one. The best I can do by way of an explanation is to suggest that they thought it would make people happy. Also possibly because they’re idiots. 

No, I don’t know. But they did, ignoring the complaints of teachers and school staff–or at least of the unions that represent them. 

That leaves repeated testing as the only way to control school outbreaks, and the number of tests (at least in secondary schools) seems to be decreasing. The government’s approved one of the vaccines for teenagers, but as far as I know that’s as far as things have gone.  

Again the number of cases isn’t huge. The fear, though, is that this is the beginning of a wave, not a few little splashes of water against the sand. It’s too early to tell.

 

So what’s the government doing? 

Well, it’s taken Portugal off its list of green countries and added it to the list of amber ones, meaning people coming into Britain from Portugal will now have to self-isolate when they get home. 

Self-Isolation? That’s quarantine on the honor system. Green and amber? They’re traffic lights. You know: Stop, go, look at the yellow light and get confused. 

All this matters because (a) the government made a lot of noise at one point about opening up foreign travel this summer and (b) some of the trashier newspapers made even more noise about it. We all want to be happy, happy, happy, so let’s declare the pandemic over.

In addition to moving Portugal off the green list, the government also moved seven countries from the amber list to the red one, so people coming from them will have to go into serious–and expensive–quarantine. 

But the story the country’s focused on isn’t the seven moves from amber to red but Portugal’s lone move from green to amber. The official explanation for it is that returning travelers risk bringing more variants home. 

So what variants is this preventing? The Delta variant–remember the Delta variant? The one that’s become dominant in Britain? Well, it’s picked up a mutation, one that’s happened before. It was seen in the South African variant (which came along too early to get itself a Greek letter). And that new mutation’s been seen in 12 cases in Portugal. 

It’s also been seen in 36 cases in Britain, so it might make more sense to quarantine travelers from Britain when they arrive in Britain but where’s the fun in that?

The last I heard, the mutation hadn’t been flagged as dangerous, although I wouldn’t say that’s definitive. Public Health England hasn’t tagged it a variant of concern, only a spike mutation of interest.

Actually, I’m in favor of being cautious about everything connected to Covid. The idea of promoting tourism right now is somewhere between stupid and criminally irresponsible. It’s the murky thinking that gets to me. First they crank people up about travel, then they try to keep out a mutation that’s already here. 

 

And what do we call the new mutation?

The new mutation is now being called–at least in Britain–the Nepal variant because the transport secretary, Grant Shapps, called it that in a press conference. Thanks, Grant. The don’t-blame-this-on-other-countries campaign appreciates your support. 

There is some marginal logic to linking it to Nepal, although it’s marginal enough that after I’d spent half an hour trying to explain it I looked at the hole I’d dug and gave up. It was pretty deep by then and I was worried about getting back out if I kept on. I’ve written to Nepal, suggesting that it change its name to Epsilon.

There’s no clear line between a mutation and a variant, so we don’t have to worry much about that.

 

Yeah, but what about the green list?

The countries left on the green list (last I checked) are Australia; Brunei; Falkland Islands; Faroe Islands; Gibraltar; Iceland; Israel; New Zealand; St Helena, Ascension, and Tristan da Cunha; Singapore; and South Georgia and South Sandwich Islands.

But any number of those countries aren’t accepting random British tourists, including Australia, New Zealand, Iceland, and the Falkland Islands. And Israel and Singapore sound less than thrilled about them, although I’m not sure that’s an outright ban. I should’ve done better research but I had to close the computer and feed the cat. As far as I can figure out, though, an awful lot of those green list countries are closed to British tourists.

It doesn’t sound like the list means much, does it? British tourists are welcome to come home from countries they can’t get into. Yes, friend, we’re on the other side of the looking glass here, and if you’ll pass around the slices of cake Alice will be happy to cut it as soon as you’re done. 

Think of the money those non-tourists will save by not going anywhere.

23 thoughts on “How long does Covid immunity last?

    • I don’t usually quote Twiiter comments, but someone on Twitter quoted a Portuguese official who objected about–oh, I don’t know, the confused decision making or murky thinking that went into the green list / amber list shuffle. “You should try living here, mate,” it said.

      Liked by 1 person

  1. Bitcoin and all these variants are equally confusing to me, and I have no interest in interacting with either one of them,
    Still masking up over here. Someone commented that they were continuing to wear a mask despite having both shots so no one thought they were Republicans.

    Liked by 1 person

    • The comment about the mask gave me a very sad sort of laugh. As for Bitcoins, I’ve been getting off-the-mark comments from sales websites ever since I wrote about people losing their bit-wallets. I swear, they must troll the internet for every mention of the word bit, then bombard the site with sales drivel.

      Like

  2. We are being forewarned about the Delta variant – forewarned is forearmed or something equally insane. Anyway, better watch out for the Variants – they are clearly out to get you.
    On a lighter note, I understand Cornwall is host to the American President and his wife tonight. Lucky them!
    If you should run into them at an ice cream parlor tomorrow, do give them my fondest regards.

    Liked by 1 person

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