A separate lab test by virologist Sandra Ciesek of the University Hospital Frankfurt painted a somewhat bleaker picture.

Exposing the blood of vaccinated individuals to different virus variants, she found that the ability to mount an antibody response to Omicron in people who had three shots of BioNTech/Pfizer was up to 37 times lower than the response to Delta.

An antibody response to Omicron half a year after a two-shot regimen of Pfizer/BioNTech, Moderna or a mixed course of AstraZeneca/BioNTech was not even measurable, Ciesek added.

Studies suggest Pfizer shot may protect only partially against Omicron

95% bei Delta. Bis zu 37fache Reduktion Delta vs. Omicron