The Food and Drug Administration said Wednesday that pharmacists can draw additional doses from vials of the Pfizer coronavirus vaccine, an effort that would expand the country’s supply of the first vaccine to win its authorization by millions of doses.
Pathetic.
Anyone else find it more than a little disturbing that Pfizer can’t measure the amount it puts in a vial?
A little issue of quality control, if the vials weren’t filled properly. Generally (having done a few Quality Management implementations in the life sciences sector, including AZ), those filling devices operate on a weight of the vial when filled. If it doesn’t meet the criterion, the vial is pushed out for quality control.
I didn’t do the Pfizer implementation, but I don’t see how this would’ve been missed in the design of the system or the filling machine.
This is pretty normal in the industry. Every process has an error range and filling is typically set such that the lower end is the desired quantity, so that no vial is underfilled.
Understood. But this sounds as though it was at least one extra dose and possibly two. That seems rather generous.
This is a great idea, and not unusual for the amount to be extra in the vial. Ask any nurse and they will tell you they end up tossing thousands of dollars worth of medication every week - a lot of times, because it is a 5 ml vial and the dose is only a part of that. As long as a professional who is observing good technique is doing this, I see no problem with it and it is a common sense way to help stretch the initial available supplies.
One thing to note is that vials are in very short supply right now. More so than the vaccine components. The supply chains for vaccines were never setup to vaccinate billions of people in a short time.
This is troubling. Where are the manufacturing controls? The amount in the vial is off by 40%? Azar and Hahn are making a mess.
Have they checked the concentration of the vaccine to make sure it really is extra full doses rather than just extra liquid diluting out the 5 doses of vaccine to a greater volume?
Again, understood. But it seems to me in terms of planning and distribution, if they were intending or expecting to supply enough for extra does in the vials sent that advice should have been understood and disseminated from the beginning. The idea is to get as much vaccine distributed as rapidly as possible, and if they can do this by putting more into the available vials, great. My issue is more with this information being released (and perhaps realized) as an afterthought rather than as part of the planned rollout. That, to me, raises questions about planning and best practices for the utilization of available materials. It’s not so much a criticism as a concern about whether the rush is causing mistakes to be made. This one may well be beneficial. What about the next one? I am by nature and experience somewhat cautious about the introduction of new drugs.
Or that IMPOTUS totally ignored the pooch he screwed.
Key Graf:
“You wouldn’t buy something before you knew it works if you had six opportunities to have one provider provide you with what you needed,” Slaoui said.
There are a number of problems with this.
There were no absolute certainties when the vaccine was being developed, but with the Slaoui statement, taken to an extreme, you end up with another opportunity, “just let everyone get infected, why bother buying more vaccine”, which we now know was indeed their policy.
I strongly suggest folks STFU about this unless you know what you’re talking about. ALL multi-dose vials have more in them then the labeled number of doses. ALL OF THEM DO. It is standard practice not to use more than labeled but folks do it ( I do it ) when it needs to be done. All Pfizer is doing is giving the OK to extra dose the vial. Given the importance of that vaccine I think that’s admirable.
You draw up 5 and give them. At that point you draw up FULL DOSES in excess of what’s labeled until that can no longer be done. Most vaccs are 1 ml volumes. As long as you can squeeze an additional 1 or 2 full does past the label go for it.
3 doses per vial
use 1 throw 2 away.
no wait
switch to little bottle, 1 dose each
need to make millions of new bottles
contact stock broker
need more money, send bill to taxpayers
do you feel it?
Sounding like Pfizer is asking those drawing the vaccine from the vials to be ‘acutely accurate’. It is after all a manual procedure.
It isn’t that Pfizer can’t measure the amount they put in the vials: it’s a matter of tolerances. The fill process is weight-based (as @becca656 noted). The weight of the vials themselves varies slightly, as does the weight of product dispensed into the vial. So, you need:
Anyone who has ever worked with a microbalance knows how time-consuming (and incompatible with automation) option 1 is. With option 2, you ask something like, “What is the 99.5 percentile of the vial weight distribution? What is the 0.5 percentile of the amount dispensed?” Once you have those answers, you can answer the key question, “What is the weight of the heaviest likely vial and the lightest likely fill?” You then set QC limits so that anything below that weight gets sent out to be checked. That is an automatable process. It has the consequence that there is going to be extra vaccine in the bottles. You can have it fast, you can have it right, or you can have it cheap. You can pick two of those things. What Pfizer chose (correctly, in my opinion) to do is to pick fast and cheap and set the process so the vials almost never (in my example above, about 3 vials per 100,000) be underfilled. If 3 per 100,000 is too high, you can tinker with the percentiles until you have it where you need it.
Now, we can compound the problem with this: there are lots of different needles and syringes that can be used. They vary in their efficiency, and that is also going to influence how many doses can be pulled from a vial.
Does this mean that depending on the needle you might NOT get a full dose of the vaccine? Or is it again the difference isn’t a concern?
I think why people are confused is they are saying there could be 40% MORE vaccine available. That’s a big difference - 5-10% would be like yeah that makes sense.
No, it means that depending on the dead space in the needle it may take more or less vaccine from the vial to give you a full dose. Even being acutely accurate in the draw, you’re going to get what you need, and a bit more.
40% is way, way, way at the high end. That assumes you can get 7 doses out of every vial, and I don’t believe that is happening. I’d frankly be surprised if they can get 6 doses out of most vials, and because of the cross-contamination risk the FDA has warned dispensers not to draw from more than one vial. I suspect we’ll end up seeing more like 10- 15% “bonus” doses. But in a crisis like this, every bit helps.
Do you work with this? If you uni-dose ( 1 ml vials ) your overage will not be sufficient to scavenge it. Lets say 0.2 ml per dose. Lost. But a 5 ml vial does has an extra full dose in it…and that can be recovered.
Stop.