Getting an mRNA "booster" when you've had the J&J vaccine

The Quarantine Zone
22

Well, not exactly. The vaccine that has tested the best may be Novavax, which is a “traditional” vaccine made of a protein subunit and an adjuvant. Yeah, it’s a shot of the spike protein itself, approximately.
Comparing the COVID-19 Vaccines: How Are They Different? > News > Yale Medicine
It did about as well as the mRNA vaccines in clinical trials, but it was tested against alpha, not against the original form. It also had fewer side effects.

And the Jansen J&J vaccine is extremely similar to the Oxford AZ vaccine, except it seems to work better, and may be a little safer.

I think there’s some randomness in how well they work in practice.

But as for mixing shots, and UK studies on mixing shots are pretty encouraging. They did find more side effects, but they weren’t scary side effects, just annoying ones (fever, tiredness, sore arm) and the immune response from the mix&match appeared excellent.

23

I had the JNJ vaccine in April. I have mixed feelings about the current situation and getting a booster. On one hand I’m anxious that I only got one shot, so I would like a second one like most everyone else vaccinated. On the other hand, I’m assuming that the data are showing similar results for JNJ to Pfizer and Moderna. What I mean is, if JNJ was failing in some fashion, someone would be yelling about it. So that’s reassuring in a weird way.

24

I have had both Moderna shots and am wondering if getting a J&J booster would be a good thing. Of course, I will be talking to my doctor about this on Monday, but what I’m reading is that different vaccines cause ones immune system to “learn different lessons” which might be helpful.

I am also having thoughts about how ethical getting a third shot is considering what’s happening in other parts of the world. While I kinda doubt that the vaccines available here could be shipped to other parts of the world without expiring, it just seems like a little wrong.

25

I wouldn’t feel guilty - that vaccine dose is already in the local supply chain. It either gets used up or it goes to waste. I’d rather it get used up.

No question that there’s a need to divert more supply away from the US if we’re not going to use the vaccines. The problem with that is, as we’ve seen with the delta variant, the dynamics of the situation can change dramatically. We could get caught in a scenario in which people stop getting vaccinated, more supplies go abroad, and then we could have a variant that causes a sudden surge in demand that crunches our supply. Hopefully the introduction and distribution of the Novavax shot will help the global situation

I digress - I wouldn’t overthink it. If you need the third dose, get it without worry.

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That might well be the case- I wouldn’t be surprised if different vaccines stimulate your immune system slightly differently.

I mean, the mRNA vaccines train your body to react to a certain specific protein present IIRC on the virus spikes, and presumably that’s a very effective immune response to provoke as far as immunity goes. But a different vaccine like J&J might train your body to react to something else, and as a result, your immune response may be a little bit different. And it’s entirely possible that the combination of them might well be better than either one.

But as far as problems having different vaccines for boosters? I doubt it.

27

Ya know, I’ve been thinking about this lately. This is not my field so I’ve never thought of it before. The classical thought is that you have a secondary immune response upon restimulation that involves immunoglobulin switching (IgM to more IgG) and selection for high affinity antibodies. Selecting for high affinity antibodies involves increasing the levels of the useful B cells and removal of B cells that make shitty antibodies. But do you really not get stimulation of naive B cells to make new distinct antibodies upon restimulation? I know the body makes a whole repertoire of B cells with antibodies that target different parts of the antigen. Antigens are not perfect, solid substances. They’re proteins and glycoproteins that have dynamic shapes. I suspect that you do get new antibodies made with every stimulation along with increased levels of antibodies made from the earlier stimulations. That’s why the booster experiments by Pfizer (I think) showed further stimulation of a cohort of neutralizing antibodies even though the vaccine wasn’t a new antigen. Certainly, mixing and matching will increase the diversity because each vaccine has very slightly different targets.

I’m going to ask around because this is bugging me. LOL.

28

Personally, if I were to pursue any sort of nonstandard vaccination (or any other sort of treatment) regime, I’d want it to be in the context of a controlled and methodological study. If a third shot or a mix of shots or whatever really does help, then we need to know that, so we can plan around it.

29

There are studies on this already. For a quick summary on mixing and matching -
https://www.nature.com/articles/d41586-021-01805-2

Here’s a nice discussion on boosters -
https://www.nature.com/articles/d41586-021-02158-6

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Sure, and I’ll bet that the authors of every one of those studies agrees that they’d like more data.

31

Or just come to Ontario. Based on supply and demand, I ended up with a shot of Astra followed by a shot of Pfizer. This combo has been studied and proved effective, but it was a bit of a crap shoot at the time.

32

US medical regulation has an extremely strong bias towards “first, do no harm” for anything medical. (And weirdly, almost completely lacks that for novel surgery.) It’s historically a result of the FDA being slow to review the approval documents for thalidomide, and dodging a bullet.

But lots of other countries have “standardized” vaccination schedules that made sense from general understanding of vaccines, despite not having been explicitly tested. The UK decided, based on a general understanding of how vaccines work, that it would likely be okay to delay second dose. They gathered data as they did it, and, to no one’s surprise, they won that gamble. The longer delay between doses appears to produce a more robust immune response.

Canada not only delayed second doses but encouraged the populace to mix and match. The data indicated that they won that bet, too.

Based on the available data, and my medical history and that of the family i am regularly in contact with, i would take a third dose today if it were offered to me. I mean, I’d be delighted if i could also be included in a study to improve our overall knowledge. But there’s enough evidence already on the table that I’d be happy to take that bet right now, if i could.

33

I would as well. Wouldn’t be my first time in a vaccine study.

34

Authors always want more data. LOL.

However, the results (Figure 3) in the paper linked below are pretty impressive. Pfizer appears to be superior in stimulating antibody responses while AZ is better at T cell responses. So a combination of both stimulates robust antibody production and T cell responses. That’s the scientific bases for mixing boosters.

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By the way, mixing types of vaccines is not that novel.

36

I’m sure they would, but in a pandemic, the speed with which you can collect data and gather data becomes a lot more imperative, and sometimes, this has to come at the expense of being certain about what the hazards are. I don’t want researchers to be reckless but there are going to be situations in which they might be wise to make an educated gamble in an effort to get more people protected faster.

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The Russian vaccine uses two different inactivated modified viruses for the first and second injection. Adding the Chinese vaccine either before or after J&J, would be like taking both doses of Sputnik V.

It’s not clear to my why J&J sought approval for the single dose regime and AZ didn’t: it’s single dose is less effective than the first dose of AZ ??? I would expect a second dose of J&J to have a similar effect to the double-dose AZ regime.

The Russians went with the mixed-vector regime to avoid boosting immunity to the base virus.

The Chinese went with the single dose because they wanted to vaccinate a lot of people quickly. Like J&J, I think it would be reasonable to expect a second dose of anything (even Sinovac) to have an effect similar to the double-dose AZ regime.

The mRNA vaccines (both?) use not a whole virus, not a spike protein, but a sub-unit of the spike protein. They did that because (1) that’s how mRNA vaccines work, and (2) because the theory (based on structure) was that the binding area of the spike protein was a stable structure that would not change. That’s the aspect of ‘betterness’ they were aiming for. If it does change, effectiveness will be dramatically reduced (???)

Sinovac is an inactivated COVID virus: it has the spike protein and the binding area, but may provoke immunity to some other structure.

AZ and J&J and Sputnik are inactivated modified adenovirus: they have the spike protein and the binding area, but may provoke immunity to some other structure.

I don’t know how the immune system selects which structures to bind to. You would think that perhaps Sinovac might be a better idea than J&J, I don’t know why China was the only one to go down that path.

Since you are trying to achieve immunity to COVID, not just immunity to one specific site on one specific protein, I think the term ‘booster’ is valid for any second injection of any of the COVID vaccines. If it boosts immunity by adding a second antibody site, that’s good. If it boosts immunity by increasing the number of identical antibodies, that’s good too. Since all the vaccines include one element in common - the stable binding site, I think it’s a good guess that all are likely to have some boostable immunity to that site ???

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The immune system is a whore, and binds to everything.

I think there were a lot is reasons each group chose what they did, including what they’d been working on and what expertise they had lying around. But early reports suggested the recovering from a mild case of covid doesn’t provide very strong immunity to catching it again, so the inactivated while virus never seemed like a great bet. And the data suggests it’s one of the less effective vaccines.

The mRNA vaccines, and i think the adrenoviral ones, too, prompt you cells to make a spike protein that was slightly modified from the wild virus. In the live virus the spike protein mostly is folded to keep the binding site hidden until it’s close to the ACE receptor it wants to stick to. The vaccines code for a version that has a slightly broken “stalk”, which can’t close, and forces the binding site to be presented to the immune system. The goal is to teach the body to make a neutralizing antibodies that grab into the binding site. That seems to have worked well.

39

All the more reason for everyone doing this to be part of a monitored dataset.

Because of the need for testing. It takes more time to test two different vaccination regimes than it does to test one, so you go with the one that you suspect will be more effective, and test it that way. And there are a lot of different ways to measure “more effective”, so different drug companies made different decisions on that count: A single dose, for instance, might offer less protection than a two-dose regime, but the ease of only having to give one dose might mean that you can get more people vaccinated that way, which might be a good tradeoff. Personally, I suspect that all of the vaccines are similar in their one-dose effectiveness, and the differences are entirely in what regime the researchers chose to test.

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COVID-19 mixed vaccine schedules - The Melbourne Vaccine Education Centre (MVEC) (mcri.edu.au)

Mid-level content, easy-level difficulty, reputable source.

41

Got the supplemental shot today (Moderna). Eight hours later, I’m starting to get the aches, slight fever, and fatigue same as when I got the J&J. My partner is having no symptoms so far, same as her first shot. Lucky her!