Why Did Some Patients Get Injected With 5X the Pfizer Covid Vaccine Dose?


Before I get into this post, I want to also point you to another post that I wrote for the Value Capture blog:

Salem Health Presentation on Their Covid Vaccination Process and Lean

Now, on to the injection mistakes discussion. When I first read about the Pfizer-BioNTech COVID-19 vaccine (a.k.a. “the Pfizer vaccine”), I found it curious that each vial contained five doses (or, sometimes, six doses — oops).

Embed from Getty Images

The vial says “DILUTE BEFORE USE.” Is also says “After dilution, vial contains 5 doses.”

That's all in pretty small print, even with the ALL CAPS for the one warning.

I figured it was a matter of time before something went wrong — the vaccine not being diluted or the entire vial being given.

You could call me cynical. I don't have a crystal ball. I'm just aware of the types. of errors that occur in healthcare, especially when people are stressed, fatigued, or rushed.

I don't know the technical or logistics reasons why, but I wondered why it couldn't come in a smaller single-dose vial. Why can't it be pre-diluted? There might be good reasons for this.

Well, I've seen two headlines that confirmed this risk, one from Israel and one from Germany:

Coronavirus: 67-year-old jabbed with five doses instead of one


Vaccine overdose puts German care workers in hospital

It might be human nature to blame the people who gave the injections. We might think things like, “What's wrong with them?” or “They need to be held accountable!” or “They should have been more careful!”

In Israel, the subheadline reads:

“This is not the first time that Maccabi staff administered an overdose of vaccination.”

If it's happening multiple times and in multiple locations, that screams “systemic error” to me.

A 67-year old woman was given five doses:

“Instead of receiving one dose during the inoculation process, she was accidentally given an entire vial – 150 micrograms.”

She was OK, thankfully, after being held in the hospital for observation. At least this doesn't seem like a deadly error. But, it certainly wastes precious doses of vaccine and might cause stress for the patient.

A professor is quoted:

“This happens for a very simple reason,” explained Prof. Cyrille Cohen, head of the immunotherapy laboratory at Bar-Ilan University. “After so many patients, the nurse, who is used to sometimes injecting the whole contents of the vile – not for this vaccine, but in general – makes a mistake and takes the whole compound instead. I am surprised it has happened only twice.”

I'm surprised it isn't happening more often.

Now, it seems like this habit of “inject the entire vial” might be more likely to occur if a nurse is injecting many different medications during a day.

Having dedicated vaccination operations where a nurse (or other provider) is doing nothing but Covid vaccinations would reduce this risk… they'd get into a new habit… but they still might fall back into an old habit.

The hospital people I've talked to say that the vials are typically diluted and drawn by a pharmacist or a pharmacy tech. Then, from the nurse perspective, they're just giving the injection with the syringe that's given to them.

The answer, I guess, to the question I asked earlier was in the article:

“Why ship the vaccines in vials of multiple doses if it risks overdosing?”If you put every 30-microgram dose into a single vile, then your shipment would be five times the volume,” Cohen said. He added that the Moderna version is shipped in vials of 10 doses each.”

I don't know how many different vial sizes are used in the industry, but the vaccine producers are limited by the vial supply chain and suppliers. They might not be able to procure the ideal, bespoke vial (even at these huge volumes).

This error is described as being rare, although I'm not sure if Cohen is estimating the risk.

“As of now, Cohen pointed out, the chances remain only one in a million of being jabbed with the entire vial.”

The risk would be higher in certain circumstances, especially if there are stressed staff and a lack of process error proofing. It's not a random chance like the lottery.

Back to the Germany article, it says eight patients from a nursing home were overdosed and were sent to hospital with flu-like symptoms.

“I deeply regret the incident. This individual case is due to individual errors. I hope that all those affected do not experience any serious side-effects,” district chief Stefan Kerth said in a statement.

Again, I think we have to be careful writing things off as “individual errors.” We should step back and think about the design of the system, including the vials and the labeling. We should ask about the training process related to the vaccine — was it rushed? Was it effective? Were people just told to read a document like this one from the CDC?


I'm not a graphic designer, but I do believe that job instructions should have “key points” and “reasons why” called out very clearly (this is a lesson from the Training Within Industry Job Instruction methodology).

The point about diluting could be more prominent on the top of page one perhaps?

The TWI JI method also teaches us to not just throw a document at somebody. We talk them through it, we demonstrate the work, we have them try it, and we have them teach back and part of the purpose is to prove the efficacy of the training attempt. We don't just assume somebody is trained, we test for confirmation.

I hope we don't see more of this happening. I wonder how often it's happened in the United States? Every error won't necessarily make the news…

Oh, people need to take care that they don't get crossed up with the Moderna vaccine, as the CDC guidelines say to NOT dilute that one.

That key point about NOT diluting is not bolded in that document.

Free Webinar on Thursday

If you're interested in the operational and process improvement details of the Covid vaccination process, join us on Thursday for an expert panel discussion webinar that I'll be moderating. This is jointly produced and sponsored by Value Capture, KaiNexus, and Catalysis.

Improving the COVID Vaccination Process: Lessons from the Field

Learn more and register here.

What do you think? Please scroll down (or click) to post a comment. Or please share the post with your thoughts on LinkedIn – and follow me or connect with me there.

Did you like this post? Make sure you don't miss a post or podcast — Subscribe to get notified about posts via email daily or weekly.

Check out my latest book, The Mistakes That Make Us: Cultivating a Culture of Learning and Innovation:

Get New Posts Sent To You

Select list(s):
Previous articleRecording: Billy Taylor & Me Doing a LinkedIn Live “Watch Party”
Next articleHide Oba Discusses His Legendary Father, Toyota’s Hajime Oba
Mark Graban
Mark Graban is an internationally-recognized consultant, author, and professional speaker, and podcaster with experience in healthcare, manufacturing, and startups. Mark's new book is The Mistakes That Make Us: Cultivating a Culture of Learning and Innovation. He is also the author of Measures of Success: React Less, Lead Better, Improve More, the Shingo Award-winning books Lean Hospitals and Healthcare Kaizen, and the anthology Practicing Lean. Mark is also a Senior Advisor to the technology company KaiNexus.


  1. It’s really important to note that the concentration is the same in each vial. Pfizer overfilled the vials to ensure that they contained at least 5 full doses dependent on the size needles use. With every dose withdrawn from the vial, there is volume lost within the needle.
    The labels of the Covid-19 vaccine, and perception labels in general, are not only confusing but dangerous. There needs to be more research and implementations that ensure that the size of the font is legible. The conventional labels have proven to be a problem for health care professionals, which is an issue given the current state the world is in.

  2. In theory it is smart to ship the vials with multiple doses in each because of the immense pressure coming from the public to get the vaccines out and take steps to get businesses open however they have clearly missed key steps in making it safe. I do not blame the nurses that are administering the vaccines because it is clear that it has not been clearly communicated with them whether or not the vaccine is diluted or not.

    I am all for getting the vaccines out but I cannot help but think they have rushed the process and it it not worth it if it ends up doing more harm than good. Before the vaccine came out there was an overall consensus that in some shape or form this process has been rushed because normally it takes multiple years for a vaccine to reach the public and the Covid-19 vaccine is already in the hands of the public in within under a year, maybe we should all take a step back for a second and make sure that this is being conducted properly.

    • Hi Jake – I don’t think the process was “rushed” but some of it might have been poorly designed (like the labels with small print). I don’t think the vaccine is “doing more harm than good.”

  3. Another example, from Singapore:

    Eye centre employee given 5 doses of vaccine by mistake

    “This occurred during a vaccination exercise on Jan 14, and was due to human error resulting from a lapse in communication among members of the vaccination team.”

    How can we prevent such interruptions in the work?

    SNEC said the worker in charge of diluting the vaccine had been called away to attend to other matters before it was done.

    A second staff member had then mistaken the undiluted dose in the vial to be ready for administering.

    I hope this is true:

    “He said that the centre has done a thorough review of its internal processes, and taken steps to tighten them so that such lapses do not occur again.”

  4. It keeps happening, this time in Australia:

    Elderly patients show no adverse reactions after being given incorrect dose of COVID-19 Pfizer vaccine

    “The medical mishap has been blamed on a doctor who did not complete the mandatory online vaccine training prior to his first engagement under the Commonwealth rollout with private contractor Healthcare Australia.”

    Is that the doctor’s fault? Or evidence of deeper systemic problems in healthcare?

    Thankfully, these errors are not harmful and are not deadly…

  5. I’m sorry, but the DOSE to be given is just about THE MOST IMPORTANT piece of information about that injection. If you don’t check that before administration you are NOT DOING YOUR JOB. Attempts to change procedures to minimize mistakes are good, but ultimately it rests on the person administering the medication.

    • I think we’ll have to agree to disagree. Do you work in healthcare, Jane?

      What if the vaccination is working in a really chaotic environment? You expect that caregiver to be super human and not distracted? Or not fatigued? If the person is not trained properly, is that their fault?


Please enter your comment!
Please enter your name here

This site uses Akismet to reduce spam. Learn how your comment data is processed.