63 Comments

As a 74yo healthy physician I have gotten the 4th dose - the big motivator for me was the admittedly uncertain effectiveness of boosters to prevent or lessen impact of “long Covid”. From a quality of life perspective, that at this point is my big concern.

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I speculated elsewhere that perhaps everyone who has been infected has, in effect, "long covid" whether they are symptomatic or not. This is due to the virus's ability to use the vascular system to colonize various organs and cause slight but long term organ damage occult to the patient. So the major benefit of vaccinations and boosters are not only to minimize risk of hospitalization and severe sickness but also to keep people from getting infected in the first place.

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I'm an MD and read the linked article to support mix/match boosters-- and to my read it showed the better durability of Moderna vs Pfizer. So, I asked an ID colleague to double check and he agreed. He doesn't see the benefit of mix and match, unless you got Pfizer and can now get a Moderna. Just 2 MD's opinions. But I really respect the infectious disease doctor I consulted.

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Thank you for this! That was my read, but I didn’t trust myself (community public/health and policy, not a medical professional)

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I had J&J for #1 and Pfizer for #2. Should I boost with Pfizer again since I technically have not had a full regimen of it or mix with a Moderna boost this time around?

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Same here, thanks for asking that question.

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I would add in a dose of Moderna for the outstanding, durable protection. J&J gave you the good T cell protection, and the mRNA vaccines will give you the higher antibody levels.

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I am 86 and had three Moderna shots, the last booster was on Nov. 6th. Then about a month later I developed loud tinnitus which I never had before and I cannot think of any event that would cause this except the vaccine. No one is talking about this so I went online and found that in this country over 13,000 people developed this after the vaccine shot. That is less than 1 percent of total shots but is very unpleasant for anyone in that group. I also found that there are no studies about this so far. I am very apprehensive about getting any more boosters, especially since I was told by an ENT doctor that it probably will not go away.

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Correlation does not imply causation.

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Thanks Katelyn for another clear and informative post. This morning I read the paragraph below, and I was hoping you might weigh in. This was from The Dispatch and came as part of a check-in with Dr. Offit at CHOP, although it wasn't attributed to him.

"But the second booster may not be entirely risk-free—and we’re not talking about those pesky side effects that can knock you out of commission for up to 24 hours. Due to a phenomenon known as “original antigenic sin,” the body’s immune response to a given pathogen tends to lock in after it first encounters a virus—or vaccine imitating a virus. Any future variant-specific vaccine will have to overcome this hurdle."

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yes i’m happy to post on original antigenic sin. i’m not necessarily worried about it in regards to a booster and side effects though. so im a little confused about that statement. it’s more about effectiveness long term, which i agree a variant-specific vaccine would have to overcome.

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Thank you! The original article did not discuss it in terms of side effects but said that there is a risk of a future variant vaccine not being able to work as well to prevent severe disease in people who got too many of the boosters.

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Yes, please comment on this. I was so happy to get my booster yesterday. Now I’m worried again.

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I'm still planning to get my second booster as I think KJ's analysis is more convincing. I'm truly sorry to cause any worry!

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That’s okay. I actually saw the same article in The Dispatch and had the same thoughts. I’m still glad about getting the booster.

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I'm 3x vaxxed, but I'm just not buying that risks of continuing to vax that frequently is just a couple of days of yuck (plus even the first data had some clot issues with Pfizer, no? So even if rare, that should still be among the risks listed). Anyway, I'm also hearing of people getting Long Covid from the vax, not just Covid. I imagine, like all the other risks, it's much more rare (and maybe milder), but with so little research on Long Covid, and with the vaccine being the only plan anyone in authority is banking on, I'm finding myself skeptical of additional doses going forward. As a high risk person, I'm going to chance the 4th, but really weary of the only data being on death - some of us worry about other possible consequences, from both covid AND the vaccine. Like are they even still tracking effects from vaccine for each additional shot? Or they're just going to assume the 13th booster is still safe based on the 2-shot series studies?

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Clot issues were with J&J and (the very similar) AstraZeneca, not with Pfizer or Moderna. There's no evidence of long covid from vaccination -- on the contrary, the vaccines protect against long covid.

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And yes, they are still tracking adverse vaccine events. The safety of Pfizer and Moderna is standing the test of time.

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Appreciate that you are updating on peer reviewed studies as they are released. Thank you

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Katelyn, thank you so much for this and all your work. So clarifying, balanced, helpful.

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Thank you for this article. I am a healthy 50-year-old and your "bottom line" comment gave me the final push to schedule my second booster. And, thanks to your discussion about mixing vaccines, I will go with Pfizer for this one (my previous three shots were Moderna). Your posts are so helpful in sifting through all of the information when so much is left to the individual to navigate. Thank you for distilling it all down for us and always following the science. You have helped to make a very overwhelming time much easier. Thank you!

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I had Pfizer initially, then Moderna for my booster. Should I go back to Pfizer for booster #2? Stick with Moderna? It’s all very confusing. Incidentally, my Moderna booster side effects were even worse (two days of yuck) than after my second Pfizer shot (one day of yuck). Fortunately I’m retired and could rest at home.

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Do repeated boosters diminish impact over time? A big question with 4 or more shots?

Your comment on mixed vaccine was most helpful as is your intelligent, thoughtful way of presenting data. Thanks for the expertise. And apologies for earlier non-edited version!

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Thanks for asking that question. Recently read a NBC report quoting a physician about concerns over “ immune exhaustion “ as they called it when too many boosters given. They referenced an HPV study as to effectiveness on multiple variants.

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Does not switching vaccines for a second booster, increase your chances of having a bad reaction, if you had little or no reaction from the first three of the same vaccine?

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Question please: I am over 65 and have had three shots of the Pfizer vaccine. Might I be able to now get the J & J vaccine? The duration and effectiveness on the J & J vaccine is most promising.

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Moderna is particularly protective for 65+. That's what I recommended for my parents.

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Katelyn, do repeated boosters stress your body in any way? Meaning, do you pay a health "cost" for a 4th booster other than side effects? I usually get a slight temp and feel run down for a few days.

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Thank you for this. I'm a healthy 53 year old, but had my booster back in Oct so I am going on 6 months, but I'm also part time in an office (Though all vaccinated) and take public transportation. I was wondering about getting a booster, so your bottom line is very much appreciated.

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What do you do as a 49 year old who used to qualify under the more at risk group, but now no longer classified as such due to the definition change. Therefore 6 months since first booster, but not technically qualified at this time based on new definition?

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Talk to your doctor. They have some discretion to administer the vaccine "off label" to patients they think would benefit, based on your medical risk factors.

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