Accuracy and repeatability, on a given day, of centralized preparation of Covid-19 vaccines in a vaccination centre.
1 Ecoles Militaires de Santé de Lyon Bron, 331 Avenue Général de Gaulle – 69500 BRON - FRANCE
2 LASEM de Toulon – Base Navale de TOULON - FRANCE
3 HIA Sainte Anne, 2 Boulevard Sainte Anne - 83800 TOULON - FRANCE
Since April 2021, the French Medical Health Service has taken part in the vaccination of the French population against the Covid-19 by setting up vaccination centres. The Military Hospital of TOULON actively participates in this mission, realizing up to 1 000 shots a day. Syringes are prepared by the military pharmacy technicians, under the control of the military pharmacists. For the Comirnaty®, vaccine, the injected dose to each patient is 0.3 mL, with syringes provided by different suppliers. Our work aimed to check the vaccine volume injected to each patient, and to identify potential technician and/or syringe type effects.
Vaccines are reconstituted by diluting the commercial solution with 1.8 mL of NaCl 0.9%, producing up to seven 0.3 mL syringes. Two brands of 1 mL syringes with pre-assembled needle (low dead volume) were tested. Our study relies on determining the volume for each prepared syringe, by a gravimetric method after the subtraction of the empty syringe weight, the measure of the diluted vaccine density and the estimated dead volume for each syringe type (colorimetric method).On Wednesday, 26th of May 2021, eight series of seven syringes for each type were weighted with a 1/10th mg precision balance, before and after preparation by two technicians, for a total of 56 syringes for each brand and technician leading to 224 individually controlled syringes over the day.
A syringe effect was observed between the two different brands, as well as a technician effect, but very limited. The injected volumes, regardless of the syringe type and of the pharmacist technician, complied with the expected standard for syringes commercialization.
To conclude with, our results suggested a better accuracy of volumes delivery than required by the CE mark of syringes (standard NF EN ISO 7886-1:2017), as well as an excellent repeatability. Furthermore, the tools we established for this study could be useful in other fields of technical Pharmacy.