Pfizer and BioNTech and announced that a three-shot course of their COVID-19 vaccine was able to neutralise the new Omicron variant in a laboratory test and that they could deliver an upgraded vaccine in March 2022 if needed, reports MedicalBrief.
In the first official statement from manufacturers on the efficacy of their vaccine against Omicron, they said two doses resulted in significantly lower neutralising antibodies but a third dose boosted those antibodies by a factor of 25.
The Omicron variant was neutralised in samples of blood taken around a month after the third shot about as effectively as two doses neutralised the original virus identified in China.
"Ensuring as many people as possible are fully vaccinated with the first two dose series and a booster remains the best course of action to prevent the spread of COVID-19," Pfizer CEO Albert Bourla said in the statement:
- 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
The findings are broadly in line with a preliminary study published by researchers at the Africa Health Research Institute, which said Omicron could partially evade protection from two doses of the Pfizer/BioNTech vaccine and suggested a third shot might help fend off infection.