The US Food andDrug Administration (FDA) issued guidance on 26th October 2011 regarding the use of injector devices to administer influenza vaccines to patients (what is sometimes called the "flu shot"). The information comes via the FDA’s Center for Biologics Evaluation and Research (CBER) which is responsible for regulating biological products.
The influenza vaccine contains inactivated influenza viruses. This is normally a mix of three influenza viruses: one influenza type A subtype H3N2 virus strain, one influenza type A subtype H1N1 (seasonal) virus strain, and one influenza type B virus strain viruses. According to the Center for Disease Control the use of three strains is because these strains are what “research indicates will be most common during the upcoming season”.
The FDA stated that healthcare professionals should not use injector devices to administer influenza vaccines, adding that all vaccines “be administered in accordance with their labeling.” Inactivated influenza vaccines have only been approved only for administration by needle injection.
A jet injector is a medical injecting syringe that uses a high-pressure narrow jet of the injection liquid instead of a hypodermic needle to penetrate the outer layer of the skin. Some pharmaceutical companies have been marketing flu shots using jet injectors. The FDA have moved quickly to halt the distribution and use of such devices.
In relation to these devices, the FDA further state:
“At this time, there are no vaccines for the prevention of influenza disease that are approved by the FDA for administration by jet injector … [they] have not been evaluated for delivery by jet injection…”
The reason is because that no safety and efficacy data for other vaccines delivered by jet injector has been submitted to the FDA for evaluation.
Currently only one type of vaccine is approved by the FDA for administration via jet injector: the measles mumps and rubella vaccine (also known as MMR). However, an alternative to the administration of the vaccine by injection is available. The FDA have approved certain nasal sprays for the administration of the vaccine (this works passing a fine mist into the nostril by action of a hand-operated pump mechanism).