7 doses of Pfizer COVID-19 vaccine in each vial with syringes in high demand

A French study proved some syringes can actually extract 7 doses in Pfizer’s Covid-19 vaccine vials. But the global supply of adequate equipment is short.

As the world is trying to inoculate the maximum of vaccine doses, a group of pharmacists studied the efficiency of various syringes and showed the seventh dose could really be extracted from Pfizer vials. But the lack of adequate equipment can limit the optimization.

In January 2020, the European Medicines Agency officially approved that six doses of Covid-19 vaccines could be extracted from each Pfizer/BioNTech vial rather than five. Each vial indeed contains a little more than the quantity contracted as a precaution to make sure all doses are actually delivered. In theory, there are about 7.5 doses in each vial of 5 doses.

But Pfizer started to reduce the delivery of vaccines, claiming for example that the European Union bought a number of doses, and not vials. While the member countries were craving for getting more doses of vaccine, it spurred a lot of debate. However, behind the controversy and the business negotiations, the discussion showed that adequate material was also essential for top-quality healthcare services.

And the optimization of each vial is possible by using specific syringes that would limit the “dead volume” left inside. The volume left in a syringe is in fact smaller with some models, limiting waste of the precious liquid. Being able to extract 6 doses instead of 5 in each vial would account for a 17% increase in the number of vaccines administered to the population. It is a massive improvement. But extracting a seventh dose would even make each vial 29% more efficient.

Pfizer Covid-19 vaccine — A study proved in-field experience that 7 doses could be extracted from Pfizer’s vaccine vials but adapted syringes are in high demand | Felton Davis

Covid created a global shortage of low dead-volume syringes

In various places like Korea, Spain, France, Finland or Belgium, healthcare providers realized that a seventh dose could be extracted. For instance, two Spanish nurses used needles usually meant to administer insulin.

A group of pharmacists working for a French hospital tested several syringe configurations in March and corroborated in-field experience. It showed that out of 8 models tested, their syringes with needles already crimped onto them offered a lower dead volume, “allowing to extract up to seven doses from a single vial”. Syringes with a dead volume smaller than 10 µL (0.01 mL) could extract a seventh dose. But such material has become in high demand. In fact, between 8 and 10 billion syringes are necessary for the world to be vaccinated against Covid-19 while less than 2 billion syringes are usually used for vaccination and immunization every year.

In January, Brazil restricted its exports of syringes and needles. In February, the Health Minister of Japan Norihisa Tamura admitted the country would be unable to extract the sixth dose because it lacked adequate syringes. However, in March, Japan allowed the use of syringes meant for insulin shots, although they are specific for subcutaneous rather than intramuscular injections. The United and the European Union also reported a shortage of needles. According to the Wall Street Journal, a U.S. Department of Health and Human Services spokeswoman acknowledged the supply was limited last May. Dr. François Lesourd, who participated in the French study, told Newsendip that “we now have the adequate syringes to extract a seventh dose in France. But in the context of a global shortage, we are still testing the efficiency of various syringes from different suppliers”.

The demand is high and the industry tries to ramp up its production. But it tends to neglect the usual production. “In France, we will soon lack the hypodermic needles, those we use for pretty much everything in hospitals, as everyone produces the needles for the Covid-19 vaccines”, warned Dr. Lesourd. The disruption caused by the pandemic has multiple collateral consequences.

Along with face masks, ventilators, medical oxygen or medical gowns, low dead-volume syringes are in fact another example during this pandemic that medical equipment is part of a complex chain in the efficiency of the healthcare systems.

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