COVID-19 : Coronavirus vaccine | Two Spanish nurses manage to get more doses from each vial

Last January, the European Medicines Agency (EMA) announced that the vials of the COVID-19 vaccine developed by Pfizer and BioNTech they provided six doses, and not five as indicated at the beginning, if the low dead volume syringes. Now, on the other hand, the Valencian nurses Ana Sola Martín and Natalia Coll García have shown that up to seven doses with specific syringes and much more precise needles.

A discovery that would accelerate the rate of vaccination and that has been endorsed by the Spanish Agency for Medicines and Health Products (AEMPS). “A seventh dose can be used if it is guaranteed that the indicated dose can be obtained -0.3 ml- and the precautions and administration indications specified in the technical sheet are followed (such as, for example, not combining the excess volume of vaccine of several vials) ”, Health has explained to NIUS. In fact, the AEMPS ensures that “Overfilling is a common practice in this type of pharmaceutical presentation.”

Mathematical calculation

Ana Sola and Natalia Coll carried out different simulation tests, always respecting the indications for the preparation of the Pfizer vaccine, in order to “maximize each vial and increase the availability of doses to have the largest number of people immunized in less time”, As indicated in Levante-EMV.

Aware that the seventh dose could be extracted “by pure mathematics”, they began to calculate. Solo explains that each vial of Pfizer contains 0.45 milliliters, those who 1.8 milliliters of saline must be added. “We thus meet 2.25 milliliter vials, from which you have to get the doses, and each dose is 0.3ml”. Thus, an r would remain in the vial0.45 milliliter emanent, which means that “there is one dose left in the vial to administer.”

This is something that “It can be achieved with suitable material and with the precision of the personnel”, He says. The most important is eliminate “dead spaces” existing in the syringes and needles so as not to lose a single drop of the dilution made, since it is “liquid gold”. To do this, Coll proposes using a 25G needle, the one used in the insulin syringe: “It is much smaller, has more dead space and is much more accurate. Therefore, we would have less losses in that ‘liquid gold’ that is the vaccine right now ”.

It would be frustrating if, with this method, you can get an extra dose (the seventh dose per vial), and have it thrown away because this seventh dose is not approved in the technical data sheet, when the laboratory itself, already on a previous occasion, made a correction in relation to the number of doses per vial, going from five doses to six doses at present ”, the nurses say.