Alk-Abello, who manufactures Jext Auto-injector pens, sent out an alert to a safety concern of some of the batches.
From the PDF I found, thanks to What Allergy?, it states (sorry about the way it pasted. I can't fix it)
This seems to affect the UK as I haven't seen anything about it in the US. I know I have UK readers and I wanted to alert you all to this.Routine testing conducted by ALK-Abelló has revealed that during the production process of the batcheslisted below the needle may have become bent, causing the needle to curl up inside the injector housingupon activation and consequently causing the pen not to deliver the required adrenaline dose.
You can read more at What Allergy? or you can continue to the PDF flier that has information on it, including which batch numbers are affected.