BERLIN—Swiss drugs regulator Swissmedic said on Wednesday it is examining potential risks in connection with bubbles that appeared in vials of COVID-19 vaccine boosters retooled to target the Omicron variant of the coronavirus.
Swissmedic said it had been informed by vaccination centers of the appearance of bubbles during the preparation of the updated vaccine from Pfizer and BioNTech targeting the original version of the coronavirus and the BA.1 Omicron variant that led to a record surge in cases last winter.
“Vials of the batch concerned contained bubbles after being removed from the fridge,” said Swissmedic, adding that the phenomenon seems to be accentuated when the syringes were prepared several hours in advance….