Why low dead-volume syringes are used for COVID vaccine injections

Why is the use of this type of syringe so important in the programme, that starts on Feb 26, and what are its importance and advantages compared to other syringes?

Dean of Universiti Kebangsaan Malaysia's Faculty of Pharmacy Associate Prof Dr Mohd Makmor Bakry, said the syringe had a minimum 'hub' (a dead space between the needle and barrel of the syringe) size that could reduce vaccine wastage, compared to regular syringes.

He said it will thus be able to maximise the total dosage that can be produced from a vial of vaccine saying that for the COVID-19 vaccine, six injectable doses can be produced with the use of the syringe.

The clinical pharmacy lecturer said according to preparation steps for the Pfizer vaccine provided on the Centers for Disease Control and Prevention website, each vaccine vial diluted with 1.8ml of 0.9 per cent sodium chloride will be able to dispense five doses of injection.

"Dead volume is the amount of fluid left in the syringe and needle after an injection.

"So, if a low dead-volume syringe is used for the COVID-19 Pfizer-BioNTech vaccine, it allows each vial of vaccine to produce six doses of injection," he told Bernama when contacted.

Echoing the same sentiment, Malaysian Pharmacists Society president Amrahi Buang said without the use of the high-tech syringe, a total of 0.08 ml would be wasted for each vial of the vaccine.

He said, since the vaccine is very high in value and expensive at this time, the use of the syringe is very important to ensure that there is no wastage and loss.

"If you use a regular syringe, at the connector between the syringe and the needle, there will be 'dead space', in which when we press the plunger, not all of the vaccine solution will come out of the syringe and enter the human body.

"So if you use a syringe with good technology, there will be less 'dead space'...based on our experience, low 'dead space' makes a saving of 0.08 ml of vaccine for each vial," he said.

Amrahi said since the syringe involves the use of high technology, the price of the syringe is slightly more expensive than a regular one.

"This syringe is usually used for expensive drugs or vaccines to ensure that there is no wastage...for normal saline, it is okay to use a regular syringe and lose 0.08 ml but not on the COVID-19 vaccine," he added.

Meanwhile, Dr Mohd Makmor said the low dead-volume syringe was rarely used, except for certain injectable drug products such as anticoagulants (blood thinners), insulin and so on.

"At the same time, many are pre-filled or a single-dose (of vaccine) and in most cases, regular syringes will be used," he said, adding that there are two types of low dead-volume syringes, namely Luer lock or embedded needles.

On Feb 17, Science, Technology and Innovation Minister Khairy Jamaluddin said the government had obtained the number of syringes needed for the Pfzer-BioNTech vaccine.

Health Minister Datuk Seri Dr Adham Baba was reported to have said that the Health Ministry needed 12 million low dead-volume syringes to vaccinate 20 per cent or six million recipients in the first phase of the National COVID-19 Immunisation Programme which will begin later this month.

He said the type of syringe was very important because the vaccine needed to be injected with a specific dosage into each individual to ensure its effectiveness.