When it begins inoculations, Japan will lose millions of vaccine doses because of a lack of the ‘low dead space’ syringes needed to extract the maximum number doses from each vial.
Japan had ordered 144 million doses of the Pfizer vaccine on the assumption that each vial equated to six doses. Low dead space syringes leave less vaccine in the syringe after injection, especially around the base of the needle, and result in minimal wastage. However, since low dead space syringes are in short supply in that country, regular syringes will have to be used which can only withdraw enough vaccine for five doses. This will result in the wastage of up to 24 million doses of vaccine.
“The syringes used in Japan can only draw five doses,” health minister Norihisa Tamura said, quoted by the Kyodo news agency. “We will use all the syringes we have that can draw six doses, but it will, of course, not be enough as more shots are administered.”
In large-scale vaccination programmes, the wasted vaccine in each vial becomes an issue. Skill is a factor in preserving the vaccine, but the amount of dead space in a syringe and the achievable accuracy also has a significant effect. One study showed that the amount that can be withdrawn from each vial can vary by as much 42% depending on the type of syringe used.
The US and EU have also reported shortages of low dead space syringes, and this may result in competition and supply shortages.
Japan is set to begin the first round of inoculations with 10 000 to 20 000 healthcare workers, and from there giving priority to other healthcare workers and vulnerable individuals. Inoculations for those aged 16 to 59 are not expected to begin until July.
Source: The Guardian
