Is It Safe to Inject a COVID Booster Before the Alcohol Prep Pad Dries?

[kyphysics]

I went with my parents today to get our COVID boosters (the latest/updated ones) and something happened that I had a question on.

When prepping the injection site, the pharmacist wiped us down with alcohol wipes prior to injection. This is normal (to clean the skin of bacteria/germs). What was slightly unusual was that she went for the injection less than 5 seconds after the wipe down (possibly as soon as 3 or 4 seconds). I could see that my dad's skin was still wet (it was glistening after the alcohol wipe) about 2 or 3 seconds before she injected.

I had this concern before and asked medical professionals about it. Most said you should wait for the alcohol to dry, while a small minority said it doesn't have to dry completely (and some said the "standard" or "convention" is just up to the provider). However, NONE said it was okay to inject when the site is still very wet. To summarize:

-most said let it dry entirely
-a few said partially dry is okay (if it's still slightly wet, that's okay)
-NONE said substantially wet is okay
[the above responses came from nurses and pharmacists that I've talked to]

When it came my turn, I specifically asked the pharmacist about this and she said alcohol only takes 1 or 2 seconds to dry. She said they do 100's of shots a day (implying, knows what she's doing). And after wiping me, she injected me also in less than 5 seconds it felt. She did give a big hand wave (to create air flow) right before the wipe, but as she created that air flow I could feel the dampness (and a stinging feel) on my skin.

My theory/concern was that if the skin still had wet alcohol on it, then it would get on the needle and possibly inside the needle injection hole (or even just on the tip/surface) and that could kill the vaccine as it came out. The reason they swab with alcohol is to kill bacteria/germs, so they don't get into the skin and cause infection, but what if you let the alcohol get on the needle and it kills the vaccine?????

The pharmacist said I would be okay, b/c alcohol dries super quick, but what if it didn't? I tend to think it's a very close call, but felt maybe it didn't dry entirely. Would this warrant concern for you and what would you do?

As someone who has had LOTS of vaccines and blood draws, this was probably the fastest I can remember anyone inserting a needle after wiping. Usually the person takes about 10 seconds or more. The speed of this person was very noticeable to me and the visual wetness on my dad's arm concerned me too (and me feeling damp too). Would you try to get another booster in this situation?

https://www.med.umich.edu/1libr/RogelCancerCenter/SubcutaneousInjection.pdf

University of Michigan had this tutorial on subcutaneous injections. It says to let the alcohol dry first (but doesn't say how long it should take - as it can vary depending on situation). Key point, though, is that the alcohol needs to DRY entirely.

 

[.Scott]

Even if it got on the needle, it would not touch a significant portion of the vaccine. If you think of the needle as a small pipe, then it's easy to imagine some alcohol getting onto the rim of the pipe. But most of that would be wiped clear as the pipe pushes through the skin and into a muscle. Then the vaccine begins moving through the pipe. Perhaps the leading edge of that vaccine would momentarily touch what was left of the alcohol - but most of it would find a clear path into your muscle.

 

[TeethWhitener]

I’m bored so let’s try some quick order of magnitude estimates. According to a quick google search, the biggest needle likely to be used for vaccination is a 22 gauge 1.5 inch. This has an inner diameter of about 0.4 mm, giving a total volume of about 4 cu mm. The Covid booster is 250 cu mm. So even if the needle was somehow completely filled with 100% alcohol, the full injection would only be less than 2% alcohol. On top of that, RNA is alcohol stable (the disinfectant properties of alcohol mainly affect proteins, not nucleic acids). I think you’re probably ok.

 

[.Scott]

Although RNA is alcohol stable, the vaccine consists of lipid nanoparticles that contain the mRNA. Isopropyl alcohol is a polarized molecule and can dissolve many lipids.

So enough of it would likely destroy the vaccine. But the exposure would be too slight to be a problem.

 

[kyphysics]

I’m bored so let’s try some quick order of magnitude estimates. According to a quick google search, the biggest needle likely to be used for vaccination is a 22 gauge 1.5 inch. This has an inner diameter of about 0.4 mm, giving a total volume of about 4 cu mm. The Covid booster is 250 cu mm. So even if the needle was somehow completely filled with 100% alcohol, the full injection would only be less than 2% alcohol. On top of that, RNA is alcohol stable (the disinfectant properties of alcohol mainly affect proteins, not nucleic acids). I think you’re probably ok.

That's some fantastic analysis!

 

[DaveC426913]

I use auto-injectors (think: Ozempic). They come pre-dosed with alcohol that gets applied to the skin even as the needle is spring-injected into me. The whole process, from alcohol prep to injection, takes on the order of one second. I can guarantee that some of that alcohol gets injected into me. Sometimes I feel the burn, sometimes not.

It may not be the same chemistry, just pointing out that this device is designed to function allowing that alcohol will get mixed with the payload.

 

[kyphysics]

Although RNA is alcohol stable, the vaccine consists of lipid nanoparticles that contain the mRNA. Isopropyl alcohol is a polarized molecule and can dissolve many lipids.

So enough of it would likely destroy the vaccine. But the exposure would be too slight to be a problem.

Thanks for both your thought posts!

I think in the future I'll just ask people doing bloodwork and injections to wait before the alcohol dries. I realize many people just don't do that (even if the negative effects may be minor/negligible). This morning, I actually had an endocrinology appointment and the nurse/NA taking my glucose pricked my finger when it was actually visibly wet (even more so than the pharmacist administering the COVID booster) and I could feel the dampness quite a bit.

It was 8:40AM and I'd been very fatigued, so I ignored it and didn't make a fuss (having made a fuss with him earlier on two other things he did). . .that reading is less important, as I get quarterly blood draws for my A1C and use a glucose monitor at home anyways. . . But, still, it's just the principle, b/c maybe one day it COULD matter for someone and if people are constantly doing it wrong it's a bad habit.

My takeaway is relief if the COVID booster was likely negligibly affected, but to still speak up next time this sort of thing happens and ask or proper drying before any needle punctures my skin (juuuuuuuuuust in case it matters for SOME case).

 

[kyphysics]

I use auto-injectors (think: Ozempic). They come pre-dosed with alcohol that gets applied to the skin even as the needle is spring-injected into me. The whole process, from alcohol prep to injection, takes on the order of one second. I can guarantee that some of that alcohol gets injected into me. Sometimes I feel the burn, sometimes not.

It may not be the same chemistry, just pointing out that this device is designed to function allowing that alcohol will get mixed with the payload.

I literally just got prescribed Ozempic today. However, CVS pharmacy (here it the U.S.) says none of their stores have had it for a month or more and they have no idea when the next shipment comes in (I live in the state of Virginia). There's a shortage everywhere here.

It'll be interesting when I start and if I experience the same thing!

 

[Laroxe]

Just for interest, the use of alcohol to clean the skin prior to injection appears to be falling out of favour. I know that in the UK and in Australia the advice is that if the skin looks clean, no prep is needed. It seems there is no advantage or indeed disadvantages to its use. Where it is used, it's usually recommended that it should be allowed to dry, as it could cause pain or irritation, though there is no evidence supporting this. To act as an effective disinfectant, a minimum exposure time should be around 30 seconds, which wouldn't be achieved prior to injections. When alcohol has been used to sterilize surgical instruments, infections have still occurred, particularly by spore forming organisms.
Virtually all of the suggested risks of either its use or not using it have no good supporting evidence, basically there appears to be no differences in outcomes.

 

[DaveC426913]

Citation?

 

[Laroxe]

Citation?

Really, most of the literature are discussion documents and clinical advice/guides based on inadequate data, this is largely due to the complexity of the methods that would be needed for such a high frequency intervention, with a wide range of subjects and with such low frequency outcomes. I did try to warn you.:) A few examples;
https://www.ncbi.nlm.nih.gov/books/NBK562932/
https://hospitalnews.com/the-alcohol-swab-before-the-needle-a-point-of-debate/

and the effects of alcohol;
https://www.cdc.gov/infectioncontrol/guidelines/disinfection/disinfection-methods/chemical.html

 

[DaveC426913]

My ever-lovin', who, among other things, was trained in phlebotomy (drawing blood), points to some systemic "logic":

If you don't swab, and they get an infection, now it's your fault.

i.e. It's the kind of thing that will need sufficient counter-evidence before it's dropped.

 

[Laroxe]

I don't know really, this would be true if the only outcome of concern was infection but there are other suggested risks that go with using alcohol swabs. It's suggested that the swabbing might act as a cue that something painful is about to happen, esp. in kids. That there is an increased risk of local reactions, increased risk of pain and even the fact that you kill most of the skin commensals could actually damage a potentially protective mechanism.

I suspect that any adverse outcome associated with an injection would possibly be blamed on the injector and you can't simply remove that risk. What evidence we do have does in fact act as counter evidence for most of the suggested risks, which appear to be so rare it makes it almost impossible to generate any evidence. Now of course we have guidelines that exist in several countries, with some qualifiers, that recommend that no skin cleaning be used, that also could have legal implications for attribution of blame.

I suspect your ever-loving, may at heart be an optimist, in believing one choice is safer than another when it comes to blame.

 

[DaveC426913]

I suspect your ever-loving, may at heart be an optimist, in believing one choice is safer than another when it comes to blame.

Optimist? No, cynical. She is saying exactly what you just said - that we continue to do it merely to avoid psychological and legal implications, whether or not there is any medical benefit.

 

[eachus]

Just some circumstantial evidence that swabbing is unnecessary. I am what phlebotomists call a "hard draw," in fact a very hard draw. I was in the hospital for a week recently, and on several occasions had two different drugs flowing into the back of my hands. They kept taking blood for different tests--or the same test to see if the drugs were having an effect. Some of my nurses could get a blood flow on the second or third try, two could get it the first try, and a few others would try, give up, and get another nurse to do it. By the time I got home from the hospital, I looked like a heroin junkie with all those needle marks.

As far as the subject at hand goes, the nurses would use the alcohol at the first site they tried, but none thereafter. If a second nurse was called in it was unusual for them to reswab, or swab where they injected. I didn't make a fuss about it, just grinned and bore the multiple tries. The two sites where they were flowing in drugs, one in the back of either hand, probably needed to be taken off and the area cleaned at some point, but they didn't do that either. Of course, one of the drugs I was getting was an antibiotic, in hopes it would clear up the rash on my right leg...

 

[Rive]

Just for interest, the use of alcohol to clean the skin prior to injection appears to be falling out of favour.

I wonder if this has any connection to the improving standards of personal hygiene, and what's the general attitude in countries with less of it...

Also, from ER standpoint?...

Of some effect of available, high quality, quality assured medical supplies?
In my childhood those thick (multi-use, locally sterilized) syringes/needles (customary for any decent horror-movie ) were still a thing in use...

 

[pbuk]

I think in the future I'll just ask people doing bloodwork and injections to wait before the alcohol dries.

I recommend that in the future you hold your tongue and let medical professionals get on with their job.

having made a fuss with him earlier on two other things he did

You will find that your healthcare experiences are a lot less unpleasant for everyone concerned if you stop telling people how to do their jobs.

[edited by mod]

 

[pinball1970]

I wonder if this has any connection to the improving standards of personal hygiene, and what's the general attitude in countries with less of it...

Also, from ER standpoint?...

Of some effect of available, high quality, quality assured medical supplies?
In my childhood those thick (multi-use, locally sterilized) syringes/needles (customary for any decent horror-movie ) were still a thing in use...

A quick look at the bacteria on the skin by area and species, Staph an obvious one that can cause infection if given a decent opportunity (hence opportunistic pathoge")

Most of the others I would have to look up!

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3535073/#BX1

 

[russ_watters]

I think the OP's question has been thoroughly answered and this is a good place to stop. Thanks everyone.