Pfizer also did lab tests and found similar results:
Quote:
- Preliminary laboratory studies demonstrate that three doses of the Pfizer-BioNTech COVID-19 Vaccine neutralize the Omicron variant (B.1.1.529 lineage) while two doses show significantly reduced neutralization titers
- Data indicate that a third dose of BNT162b2 increases the neutralizing antibody titers by 25-fold compared to two doses against the Omicron variant; titers after the booster dose are comparable to titers observed after two doses against the wild-type virus which are associated with high levels of protection
- As 80% of epitopes in the spike protein recognized by CD8+ T cells are not affected by the mutations in the Omicron variant, two doses may still induce protection against severe disease
- The companies continue to advance the development of a variant-specific vaccine for Omicron and expect to have it available by March in the event that an adaption is needed to further increase the level and duration of protection – with no change expected to the companies’ four billion dose capacity for 2022
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https://www.pfizer.com/news/press-re...micron-variant
So 2 doses will likely not be very effective against infection, while 3 doses (at peak protection at least) should work somewhat well. It'll be interesting to see how effective a targeted booster will be. The multivalent Moderna shot that targeted both the wild-type and Beta showed excellent results (it generated an antibody response that was about 2-3x what the single-variant shots did against each variant), so I wonder if they'll do a Delta/Omicron shot.