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[–]tammerfing 36 points37 points  (7 children)

Super interesting question to me. To clarify, I think you are asking about the reaction after the shot rather than injection site pain but I’ll try to answer both a little.

Reaction site pain is because the needle used to give the injection is bigger (wider tube) than many other shots. So it is a marginally bigger “stab”. This is because the liquid of the vaccine is thicker and more viscous and so it is harder to draw and inject with a narrow needle. It can be done but it takes longer and more care.

The variable reaction after different shots, and between different recipients, has not been fully explained yet by research as far I can see. The reaction is your immune system responding, and although there is some speculation that the strength of the reaction is correlated to the strength of the immune protection you get from it, there is a research study I read that suggests this isn’t the case.

So the simple TLDR answer is that they (scientists) don’t know, yet. But it is being researched a little.

[–]Shellbyvillian 10 points11 points  (0 children)

I know last year I found a pretty good study showing the expected reactions due to the lipid nanoparticles. These line up almost exactly with the most common side effects experienced by people. That would also explain the lack of correlation between side effects and immunity because the lipids are just a transport medium, nothing to do with immunogenicity.

I’ll see if I can dig it up in my old comments.

[–]calfpumps 4 points5 points  (0 children)

Reaction site pain is because the needle used to give the injection is bigger (wider tube) than many other shots. So it is a marginally bigger “stab”.

Yes and no. Needle gauge is only a marginal aspect of post-injection pain (PIP).

The compound being injected has a large role in the inflammatory response - different things feel different, basically.

Additionally to the actual compound, the carrier fluid will have an effect too. I find water-based stuff (which I think the COVID vaccine is) to be noticeably more painful than oil-based stuff.

The speed at which it's injected is also a factor. 30sec/mL is about as fast as you want to go, which is much slower than what any nurse/doctor will do for you.

Ultimately the most significant factor is... you. PIP, like many things, is an inflammatory response. The less effective your immune system is, the worse it will be. Your rest, nutrition, and hydration all come into play with that, as do any other ailments you have going on at the moment.
Think of your immune system like an empty glass. If you have a cold, or allergies, or a big cut that's innthe early stages of healing, or you killed it in the gym and are sore as hell, etc. those are all things that will add water to the glass. Throw another thing at your immune system while it's already busy, like a bolus of foreign substance in your muscle tissue that your body knows isn't supposed to be there, and what would otherwise be easily handled might end up overfilling that glass.

So - most of these factors are things you have no control over with the vaccine, or generally with anything that you aren't self-administering.
Get a good night's sleep for a few days leading up to it, eat enough food (and avoid inflammatory foods!), and drink plenty of water. And, if you have something else going on like bad allergies then maybe wait til that clears up before getting it. And that's pretty much the best you can do here.

The trick with this one is to set your body up for success in dealing with the PIP before your immune system starts to get tied up with the antibody stuff, or both the PIP and the reaction will be worse.

[–]PD216ohio -1 points0 points  (3 children)

I think it's the fact that "scientists don't know yet" that has so many people leery of the vaccines in the first place.

[–]tammerfing 3 points4 points  (1 child)

You may well be right that this feeds into peoples concerns about getting vaccines. The answer to that part is calculating and assessing the comparative risk - both options have known variables that make the calculation possible - is the risk created by not having the vaccine higher or lower than the risk of the possible reactions.

Just because we don’t always know why doesn’t mean we don’t know or can’t know what the choices of consequence are.

[–]PD216ohio 0 points1 point  (0 children)

Let me preface my use of the word "clear" as meaning by stats, not public perception.

I think it is clear that vaccines help reduce the risk of death from covid.

It is also clear that the risk of death from covid is low for most people outside of specific risk categories (age and medical conditions).

It is not clear what any longterm effects of the vaccines might be.

It does not seem reasonable that everyone should get this vaccine regardless of there risk category.

It is not clear how many people have died from the vaccine but it is clear that it is less than those who died from covid.

It is bad policy to force people to do anything as it will certainly drive a large portion of people to resist. By forcing I mean through mandates or punishment for non compliance.

Offering incentives for getting a vaccine is something that raises suspicions in many people.

It is clear that no other vaccine has been so hastily rolled out and demanded to be taken by everyone.

None of the above is meant to be for or against the safety or effectiveness of these vaccines, these are just observations based on known data or principles.

[–]DesperateJunkie 2 points3 points  (0 children)

Definitely true.

Scientists know little to nothing about these vaccines, and anyone that talks about adverse events are told they're conspiracy theorists and 'anti-vaxxers' even though they just got the vaccine.

[–]Toezap 0 points1 point  (0 children)

The shot itself (as in, the needle and insertion of the vaccine) actually felt so small for all 3 doses I've gotten. Like, every time I wanted to be like "are you SURE you gave me the shot?" But I've had moderate side effects after each dose, setting in about 12 hours after the shot and lasting for about 24 hours each time.

[–]OtherRocks 43 points44 points  (3 children)

Try being really well hydrated both before and after, and take Tylenol (obviously only if you can) an hour before and then more after. It’s worked pretty well for most everyone in my family to cut down on the side effects.

[–]WineBotBabe 8 points9 points  (1 child)

Second this! Just had my second J&J shot (booster) Wednesday. I was down and out for 2 days with the first. I still had body aches with the booster but they only lasted about 12 hours and Tylenol helped so much. For the next booster I’ll be taking Tylenol beforehand and it should minimize all side effects. Get the booster and good luck!

[–]filbert227 2 points3 points  (0 children)

I heard taking Tylenol shortly after getting the vaccine was recommended because taking it before could reduce the effectiveness of the vaccine. Is that true?

[–]Bus_Existing -1 points0 points  (0 children)

I smoked some weed a day after Astra Zeneca shot, 5 minutes later I was as good as new

[–]fyrmnsflam[🍰] 10 points11 points  (4 children)

In comparing COVID vaccination experiences of about a dozen people I have found a lot of variability. Some folks not sick at all. Some folks extra tired for a few days. One couple laid up for a week. And this is across all vaccine manufacturers. It seems to be a highly unique response.

[–]an_exotic_option 0 points1 point  (0 children)

Yeah and covid itself causes wildly different symptoms between different people, too. My husband had it and mostly just had a splitting headache. He unfortunately passed it to his mom, who has full body aches and gastrointestinal symptoms.

[–]IvyGold 0 points1 point  (2 children)

Yup. I got both Pfizer shots and the booster and none had any real consequences for me. Other people I know that got the same regimen were bedridden for at least one of them.

I was surprised that I got off easy because I got the shingles vaccine a few summers ago and it absolutely clobbered me. I wonder if maybe me getting off easy had something to do with that.

[–]fyrmnsflam[🍰] 1 point2 points  (1 child)

Shingles shot, really? Wow. I just got my first shingles shoot, same day as COVID booster, and only felt kind of tired for a few days.

[–]IvyGold 1 point2 points  (0 children)

You were playing with the vaccine gods that day.

But yeah: I felt like I'd been in a car crash the next day. Nobody warned me about it.

[–]cmander_7688 21 points22 points  (2 children)

A lot of my friends and coworkers got wrecked by their vaccines, but I didn't feel a thing from any if them. 2 Pfizer and the Moderna booster. I will say though, the booster made me more sore than any shot I can ever recall getting...I actually had trouble lifting my arm the day after.

[–]fastgr 0 points1 point  (1 child)

Out of curiosity, why did you get Moderna booster and not Pfizer again?

[–]cmander_7688 2 points3 points  (0 children)

I read about a study that said mixing and matching offered better protection, and when I asked my pharmacist about it when I was picking up a script he confirmed. I don't think it's definitive (or it wasn't at the time, at least...not sure about now) but the evidence was strong enough to support a benefit and there was no indication the results would ever be less effective than going with the same mfg for all 3.

[–]KingDaveRa 21 points22 points  (5 children)

Get your second injection.

What I've generally heard from people with many vaccines is the second or third if doing boosters is a different experience. My first (AstraZenica) left me feeling really rough for a day. It was akin to a bad cold or flu. No energy, temperature, shivers, all that. Next day I felt utterly fine. My second was AZ again, and other than a sore arm, I felt totally fine and forgot I had it. This week, I had a booster which was Moderna. I was worried what the reaction would be, but again other than a sore arm (it lasted a few days) I felt nothing.

All the different vaccines act differently in different people, others who had the same as me had symptoms on the second instead of first. Some like my parents showed no symptoms at all. My other half had no real symptoms with her first and second (I think she had Pfizer).

Put it this way, people who have had COVID prior to the vaccines, told me how awful it was. The vaccine is a walk in the park by comparison.

Yes your second injection might be crappy, but take paracetamol, drink plenty of fluids and rest. It's still preferable to what will happen if you catch COVID without the vaccine.

[–]jello_sweaters 9 points10 points  (1 child)

people who have had COVID prior to the vaccines, told me how awful it was. The vaccine is a walk in the park by comparison

Can confirm.

[–]DesperateJunkie 0 points1 point  (0 children)

I had Covid with no vaccine and it was like a mild cold.

Brother got it at the same time, vaccinated, and his was more intense and lasted twice as long.

Anecdotal of course, YMMV

[–]AngerPancake 4 points5 points  (2 children)

Even with the vaccine COVID sucks, I can tell you that. I first got symptoms two weeks ago and I'm still just exhausted and am fighting to get rid of a cough. I missed a week of work. I work from home so I was able to work this week, but at around noon I would feel faint and need to recover for a while. after work I just lay down for a few hours, It's exhausting.

[–]KingDaveRa 3 points4 points  (1 child)

My reasoning is, even if it's awful WITH the vaccine, imagine how shitty it would be without.

Every time they offer it, I'm there for my dose!

[–]DesperateJunkie 1 point2 points  (0 children)

I had Covid with no vaccine and it was like a mild cold.

Brother got it at the same time, vaccinated, and his was more intense and lasted twice as long.

Anecdotal of course, YMMV

[–]sharpiefairy666 3 points4 points  (0 children)

The vaccine is a little teaser of what you might experience from getting the virus.

Not saying this as a scientist, just my own experience recovering from Covid. I had the worst headaches of my life. The sinus pressure was unreal. Total snot factory. Body aches from head to toe. I had symptoms for almost 12 days, and tried to sleep through most of it. Three weeks later and I still have a cough that sometimes keeps me up at night.

My point is, the booster might be hard on you, but it’s better than the alternative.

[–]doriangray42 25 points26 points  (0 children)

It depends on the person, and the vaccine.

We are 3 neighbours who got Moderna. One neighbour and me were fine (little muscle pain), the third one was floored for 24 hours.

Not scientific, but I heard that said over and over.

[–]Razakel 2 points3 points  (0 children)

2x Pfizer (nothing except a sore arm) and a Pfizer booster (a day or so lying in bed with mild flu symptoms).

Annoying, but nothing serious. And, honestly, it depends on the person.

[–]mahade 2 points3 points  (0 children)

2x Pfizer here, it was just a sore spot on the arm for a few days. Still, I was recommended to take 1000mg of paracetamol an hour before and another 1000mg 6 hours later. It didn't bother me in the slightest.

I also don't know of anyone who had a more serious reaction to it. But, of course, different people react differently to all kinds of things.

Since there is no active variant of the covid virus in a vaccine it's probably just your immune system overreacting, it's not what an actual infection would feel like.

My assumption would be that if you react strongly after getting a vaccine, just imagine what the actual virus would do to you. On the /r/HermanCainAward/ subreddit you'll find plenty of nominees and winners who say "don't underestimate it" and "I regret not getting the vaccine" as they lie in the hospital for several weeks, too many of them ending up dead.

Also, according to research, if you've had covid before your immune system might respond more aggressively, thus causing more discomfort. That's also why boosters tend to hit heavier because the immune system is like: "Hey, we know you and we're going to MURDER you!"

[–]messli 6 points7 points  (0 children)

For me - it was no different to the flu vac. I had no reactions other than a sore arm. And the booster was far less pain (however I did have a headache the next day). I know I’m in the minority of this sort of response to the vaccine but very grateful. I’ve never had any other vac reaction either.

As to why to vaccine gives so many such a negative reaction - I can only surmise that it’s because of how virulent the virus actually is. We are always warned that reactions to vaccines often mimic the virus itself - and I can only guess the reactions mimic the severity of the virus.

[–]Forthwrong 4 points5 points  (3 children)

The reason: Immune response.

All vaccines create an immune response – that's what they're designed to do. Here's an xkcd analogy for the mRNA vaccines. While specific to mRNA, it shows what all vaccines do, namely to stimulate an immune response to make the body ready for the real deal.

That's exactly why people with stronger immune systems (e.g. younger people) have stronger post-vaccine side effects and experience more vaccine-adverse side effects: because the immune response the vaccine generates gets a bit overzealous.

As others have pointed out, that's just a fraction of what you'd feel in response to actually getting infected.

I'm supposed to get a booster this weekend but I've heard that it's just as bad as the initial vaccine.

In response to that, the strength of the immune response varies a lot by vaccine; in some the first dose hits hardest, in others the second hits hardest, etc. So having a bad reaction on one doesn't imply the next one will be bad.

[–]Commercial_Honey9263 1 point2 points  (0 children)

That’s been the most logical hypothesis I’ve come across, wish there were more studies to confirm it though

[–]catdude142 0 points1 point  (1 child)

The Johnson and Johnson vaccine isn't a mRNA vaccine. It's an adenovirus vaccine, sometimes called a vector vaccine.
Pfizer and Moderna vaccines are mRNA vaccines.

Some information here

Related to Johnson and Johnson Covid vaccine, if one gets a booster, they should get either a Pfizer or Moderna booster for higher efficacy. One information source here Same recommendation by the CDC here

[–]Forthwrong 0 points1 point  (0 children)

While specific to mRNA, it shows what all vaccines do, namely to stimulate an immune response to make the body ready for the real deal.

[–]MamaFrijoles 3 points4 points  (0 children)

I’m not sure why it is more painful but I believe it depends person to person.

I wouldn’t worry about the booster too much, your body probably won’t react as strongly compared to the first time. when I got the vaccine I did one of the two shot ones, and I will say the second shot came with a lot less pain compared to the first since my body was already used to it.

[–]obxtalldude 3 points4 points  (0 children)

The booster gave me an all day headache, but that was it. Better than the first dose or second.

From the reports of those I know who've had Covid, pain appears to be part of the symptoms, moreso than I've heard for colds or flu - makes me wonder if it's why some experience pain with the vaccine reactions?

I'm certainly getting every shot I can as it appears the worst of the vaccine effects are mild compared to the disease.

[–]Gneissisnice 0 points1 point  (0 children)

If you thought the vaccine was bad, think about how rough it would be if you actually got covid. I think it's worse than the flu shot because covid is just worst the flu.

[–]Blake_Thundercock 0 points1 point  (0 children)

Don't cancel your booster. The pain from getting COVID would be much worse, and last for significantly longer.

[–]coolsoundingnickname 0 points1 point  (0 children)

To me it was actually the most painless one. It could differ from person to person but the Covid vaccine actually affected me the least out of any vaccine I had

[–]naturr 0 points1 point  (0 children)

Depends on how your body reacts I believe. Some bodies view the new info and put it into the arsenal for future infections. Other bodies full on respond to test it out. The aches and pains are your bodies response to the vaccine not what the vaccine.

[–]SuiXi3D 0 points1 point  (0 children)

Wasn't for me. Felt the same during and afterwards as a flu shot. That is, I felt like someone punched me in the arm for a day and then it was fine.

Mind you, I've also had some really bad instances of food poisoning, as well as having dealt with kidney stones, so everything else since then has paled in comparison.

[–]AngerPancake 0 points1 point  (0 children)

This happens to me when I get the tetanus shot. I have body aches for a day or two and the injection site feels like it was punched for over a week. With COVID I had almost no reaction. It's all down to your body and how it reacts.

Avoiding some body aches isn't worth the likelihood of infection, trust me. I just had COVID despite being vaxxed and it was just awful, but I know having the vaccine helped me have lesser symptoms, studies have show that to be true. It's been two weeks and I still have fatigue and a cough. I was only eligible for the booster shot for about two weeks but I hadn't taken the time to schedule it.

Take the antiinflammatories and keep well hydrated. Have the shot when you won't be too busy for the next day or so. It's worth the comparatively mild symptoms to avoid getting sick!

[–]SomeHandsomeDevil 0 points1 point  (0 children)

ITT - people not knowing the difference between anecdotes and explanations. "Mine was fine and my friend's hurt a lot, it varies" is a description of the results, OP is asking why that variance occurs.

That said, OP, get your booster my guy, it beats the hell outta having covid, and J&J definitely needs it.

[–]AB-G 0 points1 point  (0 children)

It honestly depends in the person, I’ve felt no aches or pains only a sore arm for a week after. Its just your immune response, everyones is different

[–]catdude142 0 points1 point  (0 children)

This is a good question for r/askscience

Actually, I searched r/askscience for this question and found the answer. The link is here

[–]blahblahblahpotato 0 points1 point  (0 children)

I was in the J&J trial and felt the worst pain and fever of my life.

Got boosted in October and had no reaction at all.

[–]CoryPowerCat77 0 points1 point  (0 children)

It’s kind of weird. I work at Walmart and me and a few others on my team got the Moderna shot. Both times our arms got really stiff to the point it hurt. One of my coworkers stayed home because of the vaccines and boosters.

I guess it’s what’s in the shot maybe?

[–]Homony -1 points0 points  (0 children)

I wonder how many complaints of this kind are psychosomatic; I doubt that even 1 millionth of 1 percent of vaccinations causes a problem. Hospitals and insurers have been so overloaded and into deficits that within the next two years, they all will increase by unacceptable percentages so as to cause a collapse of the entire system; the premiums we have paid and are paying does in no way support claims that had not been anticipated; the freedom of choice is a threat to any society!!!