Do vaccines keep us from transmitting Covid?

One of the endless unanswered Covid questions has been whether people who’ve been vaccinated will still spread the disease, and evidence is piling up that they’ll spread it less. 

During their early trials, Pfizer didn’t test for asymptomatic cases, but AstraZeneca did and they fell by 50%. That matters, because asymptomatic people can still spread the disease, so fewer cases means less spread. Not to be outdone, Pfizer did its own study and reported that one dose of vaccine cut the risk of transmission by 70% and two doses by 85%. 

Don’t put too much weight on the differences in those numbers. They were measuring different things.

In Scotland, people living with vaccinated NHS staff were considerably less likely to catch the virus than people living with unvaccinated NHS staff. 

How much less likely? Considerably. Will you stop asking awkward questions?

Irrelevant photo: More daffodils.

Hospital workers in Cambridge showed a 75% decrease in asymptomatic infections, and an Israeli study showed that when vaccinated people did have infections they had lower viral loads, which would make them less infectious than people with higher viral loads. 

So if we’ve been vaccinated, can we throw a party for a few hundred of our closest friends as long as they’ve also been vaccinated? ‘Fraid not. The British government’s advice is that “the full impact on infection rates will not become clear until a large number of people have been vaccinated” and we should please keep our heads on straight and be cautious. 

Why? Well, consider what’s happened in Chile. 


Okay, what has happened in Chile?

It’s vaccinated about a third of its population with at least one dose–it’s vaccination program has been impressive–and even so it’s going into another wave of the pandemic. Both deaths and case numbers are rising and they’re threatening to overwhelm the health system. Some 20% to 30% of the country’s medical professionals have gone on leave because they’re exhausted, wrestling with health problems of their own and with thoughts of suicide.

“When transmission rates are high, the vaccine does not rein in new infections right away,” said Dr. Denise Garrett, an epidemiologist at the Sabin Vaccine Institute in Washington. “And with the new variants, which are more contagious, we’re not likely to see a big impact until the vast majority of the population is vaccinated.”

According to Dr. Francisca Crispi of the Chilean medical association, the government unlocked the country too quickly. It reopened its borders and loosened restrictions on businesses. It introduced a permit system that let people go on summer vacations–or holidays, if you speak British. So people came into the country. People went out of the country. People traveled around the country. Gyms, churches, malls, restaurants, and casinos reopened. Experts fretted, but the government stuck with it, reopening the schools at the beginning of March. 

Nobody traced anybody.

And it all felt so good.

So no. No parties for the time being. Sorry.


The mass testing report

A study of mass Covid testing in British universities and colleges reports that it was haphazard, expensive, and a lost opportunity.

The BMJ–a medical journal–sent freedom of information requests to 216 schools and got full information from only 16, leading me to think that information may be free but it’s still elusive. But never mind that. They got partial information from others and it was enough to draw some tentative conclusions.

The testing was part of the government’s Operation Moonshot, which was going to make the country Covid safe and avoid a second lockdown by testing people–lots of people–whether they had symptoms or not. Since it started, we’ve had not just a second lockdown but also a third.

Never mind, though. It’s been a good use of £100 billion. 

The university and college testing was just a small part of Op Moonshot, and the study estimates that every positive test result cost £3,000. It also says that’s likely to be a massive underestimate because it doesn’t include the staffing of test sites and whatever other costs are hidden under the rug. 

You’d noticed that the rug was lumpy? I tripped on it just this morning.

Angela Raffle, consultant in Public Health and honorary senior lecturer at Bristol University, said the testing program was “a desperate exercise in trying to get favourable publicity for number 10, trying to get rid of the Innova test mountain, and trying to change the culture in this country so that we start to think that regular tests for everybody is a worthwhile use of public resources, which it isn’t.”

Number 10? That’s the center of the British government.

And the Innova test mountain? It’s made up of £1 billion (as far as I could figure out) worth of quick-result Covid tests that the government bought and which turn out to work best on people who have a high viral load. In other words, they’re exactly what you don’t want to use on asymptomatic people–the program’s target audience. 

And they’re even less accurate in the hands of non-experts. 

So who’s using them? Non-experts. 

We’ll skip the most confusing of the numbers involved in this and settle for these: Let’s say you use them to test 100,000 people and get 630 positives. Of those, 400 of those will be false positives, and you will have missed half the positive cases (that should, I think, be 230) in your sample. If that isn’t worth £1 billion, I don’t know what is. Or even £100 billion. Because what’s £99 billion between friends? 

Regular testing of secondary school students was rolled out this spring, although it’s too early for anyone to have statistics on how effective or expensive that will be. The program was sold to us as a way to reopen the schools safely. 

Stephen Reicher, a member of Sage, the government’s science advisory group, said, “The government keeps on seeking quick fixes based on one intervention. What they consistently fail to do is build a system in which all the parts work together to contain the virus.” 


Vaccine passports vs. mass testing 

All of this is particularly relevant because Boris Johnson–our prime minister when he’s working, which he does sometimes do–just backed off his plan to introduce vaccine passports and announced that we’ll use mass testing instead. But only in England. Scotland, Wales, and Northern Ireland are doing whatever the hell they want because that’s how it works around here. 

Are you confused? Then you understand the situation.

The vaccine passports were supposed to allow people into crowded events, but MPs from across the political spectrum opposed them, including a good number from his own party, and they were joined by an assortment of civil liberties groups he wouldn’t normally listen to but what the hell, let’s mention them anyway. They’re particularly problematic because not everyone’s eligible for the vaccine yet. 

So instead of vaccination passports, everyone in Britain is going to be offered two rapid Covid tests a week. 

How many of us will use them? My best guess is not many, given the odds of coming up with a false positive and having to self-isolate. For someone who’s retired, that’s a minor inconvenience. For someone who’s working and can’t afford to miss a paycheck, that’s a disaster. 

The usual suspects are saying this would work better if people were paid enough to live on when they can’t work. And if the contacts of anyone who tests positive were traced effectively.

The usual suspects will be ignored. 


Last weekend, the government announced a pilot program of nine events to try out Covid passports. Presumably that was before it abandoned the idea, who your guess is as good as mine, which is roughly as good as theirs. Five of the nine venues said they had nothing to do with the program. 

You have to love this government. It’s a gift to satirists everywhere. If only it wasn’t supposed to run the country as well.


Other vaccine news

Russia has announced a Covid vaccine for animals, Carnivak-Cov. The idea is to prevent the virus circulating in dense animal populations, where it can mutate and spread back to humans. 

And Pfizer reports that its vaccine is effective in kids between 12 and 15. It’s still testing kids between 5 and 11 and any minute now will begin tests with kids between 2 and 5. All of that’s important because although kids are less susceptible to Covid, they can sometimes get very sick indeed and can less rarely get long Covid after a mild bout of the disease. 

They can also form a nice reservoir where the disease can sit and breed before returning to the more susceptible adult population.


And your light relief for the day is…

An art director, David Marriott, was stuck in Australian quarantine after flying back from his father’s funeral and was going ever so slightly nuts with boredom, so he made himself a cowboy outfit out of the brown bags that his meals came in when they were left at his door.

Then–as anyone would do–he realized that any serious cowboy needs a horse, so he made one, also from brown paper, but plus the ironing board and a lamp. Its–or, I guess, his–name is Russell, and Marriott’s asked for a pet walking service.

The photos are worth clicking through for–not just Marriott brushing Russell’s teeth, but Russell lined up to use the toilet since the management turned down the pet walking request. Russell’s in quarantine too.

Marriott’s thinking about adding a cat and a dog next. 

33 thoughts on “Do vaccines keep us from transmitting Covid?

  1. Ellen, I’m to the point that whatever claim is being made about Covid, the vaccines, side effects, prevention measures, case stats, etc, etc, I don’t believe anything. With each article I read from the scientists and other “experts,” I ask myself: Who is this person? What is his/her stake in this? Is Big Pharma in this expert’s stock portfolio? Is this going to further this expert’s political agenda? Both ends of the political spectrum have made the pandemic a political issue, so that is going to color any opinions. I’d like to see a politically neutral person with no financial interest and no ego or ambitions involved (or maybe a machine!) carefully weigh all the established facts and present an unbiased conclusion. But since that’s never going to happen, I’ll keep coming back to see what YOU have to say! 😁

    Liked by 3 people

    • I’m flattered. Especially since–as you’ve probably figured out–I’m far from politically neutral. For what it’s worth, though, when I sneak my thumb onto the scales, I’ll point it out.


  2. You’ve done two good things for me this morning: 1) Made me feel better about not being able to wander around the UK right now. 2) Made me laugh so hard at Marriott and Russell that I nearly lost the coffee I just drank. I promptly sent that one off to all my friends to share that creative amusement while we huddle in our homes to avoid the thousands of tourists who wander around here, mostly without masks, during spring vacation time. We still have all this week to go before we tentatively emerge next Monday. While all my friends are vaccinated, we fear getting a mild case or long covid or being a carrier. San Luis Obispo County Public Health releases daily covid numbers 5 days a week. Today we’ll find out about the weekend. A surge is inevitable. So 3) you’ve provided the info that will keep us careful. Off to look at the cowboy and the horse again as I need another laugh.

    Liked by 2 people

    • It always makes me feel good when I find out I made someone laugh. Especially this year, when we so seriously need it.

      I worry about the mild Covid/long Covid threat too. I don’t think much is known yet about how likely the vaccinated (or in my case, semi-vaccinated) are to get long Covid.

      Liked by 1 person

  3. Marriott would be the best person ever to quarantine with. As would Russell…even though he’s not a person…or an actual living horse. In other less fun commenting: variants and mutations will keep this virus present in our lives. I want to know how many times the original, and now the new variants can mutate before they just get tired and give up…

    Liked by 2 people

    • Hmm. You think it might? My sense is that–well, picture it this way: You have an infinitely large handful of dice. You get to–or more likely, have to–roll them an infinite number of times. I’ll stop before I ask how long it is before they all come up sixes–it’s probably not that small a chance–but surely the mutations can go in any direction.

      If we’re working with an infinite number of dice, I should move the coffee table out of the way, shouldn’t I?

      Liked by 1 person

      • You surely should. My attempt at wishful thinking has nothing to do with reality, clearly! Covid, not unlike the flu virus, is opportunistic and will continue to replicate and mutate even after newer vaccines/boosters come into play. For those of us at a certain age, Covid, and it’s offspring are our future. I can only base that claim on the documented length of time it took to (almost) eradicate polio.

        Liked by 1 person

        • On a cheerier note, a lot of work is being done on treatments that will stop a Covid infection before it becomes dangerous. And at long last, more attention’s being paid to ventilation. So we’re not entirely reliant on all the dice turning up as sixes.

          Liked by 1 person

  4. I suppose it’s partly schadenfruede (or however you spell it) but it is some comfort over here because everything is about the same. I did get my second shot last Friday, but other than possibly sitting outside and having a coffee while a friend and I shout across a couple of tables at each other I have no grand plans.

    Liked by 1 person

      • Ha! ha! I didn’t think you did. I remember a FoI request came into the school I worked at and management were tied up for weeks trying to deal with it and that was back when nothing much was happening in the world. It was all about teaching kids and no pandemic. I should think they just lost the will to live with the amount of stuff they have to do these days!

        Liked by 1 person

          • They had a request for information about 1 pupil and they had to track down all emails that mentioned of that pupil as well as reports. If that was a troublesome pupil that could be a lot of emails from staff to other staff about missed detentions, lack of homework etc. A lot of tracking down to be done. I had never heard of the pupil concerned (it was a massive school I worked in at the time) but management had spent weeks gathering all this information.

            Liked by 1 person

  5. I’m sorry for not commenting on the serious portion of your post. I’ve nothing pithy or witty to add. But that chap in Australia – what a hoot! Do you think that Harry saw the story & packed lots of brown paper bags into his luggage to give him something to do in whatever royal hovel he’s holed up in for quarantine purposes? I say “whatever”, as the press seem to be vacillating back & forth over the location, with the headline and content of a single article detailing conflicting options. Yawn.

    Liked by 1 person

    • I suppose this might go over a royal’s head, but I think half the joy of creating the horse and all its gear was having to scout out the materials. So packing it to take with you? Nah. That’s right up there with assembling a Lego set according to instructions.

      Oops. That’s what people do, isn’t it? Deliberately. For fun. Sorry. Speaking of things that go over people’s head, that goes over mine.

      Liked by 1 person

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