Formation of bubbles in Comirnaty Bivalent Original/Omicron BA.1 vaccine: Swissmedic analysis reveals no indications of risk

Results from laboratory analyses now available


Swissmedic has examined vials containing the vaccine Comirnaty Bivalent Original/Omicron BA.1 in its OMCL laboratory. The analysis did not reveal any specific problem with the vaccine. Physical factors such as differences in pressure or temperature when preparing the doses may have been responsible for the bubbles. It is essential that doses be prepared in accordance with the manufacturer's instructions.

On 2 November 2022, Swissmedic undertook a risk assessment of the Comirnaty Bivalent Original/Omicron BA.1 vaccine owing to the formation of bubbles. Laboratory analysis of the vials did not reveal any indications of a specific problem with the vaccine.

Batch GE8297 may still be used for vaccinations. There is no risk to persons who have already been vaccinated.

Bubbles form in fluids due to physical factors. With vaccines, that relates mainly to differences in pressure or temperature (deep-frozen versus fridge or room temperature) when preparing the doses. Unlike the monovalent vaccine, which had to be thawed and diluted before use, the bivalent vaccine only needs to be thawed.

Properly functioning reporting process

Swissmedic is interested in any reports of anomalies affecting medicinal products. Thanks to the professional work done by the vaccination centres, the reporting process functions in line with expectations. When preparing the vaccine doses, it is important for the manufacturer's instructions (as per the product information) to be strictly followed. In addition, it is recommended that syringes for the vaccine should not be drawn up more than 15 minutes before use (injection).

Swissmedic is continuing to analyse the situation and will investigate any more phenomena reported. If there are further findings, Swissmedic will report them.