Pfizer Inc. (NYSE: PFE) and BioNTech SE (Nasdaq: BNTX) today announced the publication of new results from two laboratory studies demonstrating that three doses of the Pfizer-BioNTech COVID-19 Vaccine (BNT162b2) elicited antibodies that neutralize the Omicron variant (B.1.1.529).
Data published in the peer-reviewed journal Science, includes readouts of sera data from 51 vaccinated individuals that received two or three doses of BNT162b2 as well as a study evaluating the neutralization potential of serum antibodies from a subset of vaccinated individuals against the live virus. Both data sets confirm previously announced initial study results demonstrating that serum antibodies induced by BNT162b2 neutralize the SARS-CoV-2 Omicron variant after immunization with three doses. In comparison, sera from individuals who received two doses of the COVID-19 vaccine revealed limited neutralization titers against the Omicron variant in both data sets, indicating that two doses of BNT162b2 may not be sufficient to protect against infection with the new variant. However, based on observations that around 85% of epitopes in the spike protein recognized by CD8+ T cells are not affected by the mutations in the Omicron variant, the companies believe two doses may still induce protection against severe disease.
Separately, data from a live virus laboratory study conducted with the University of Texas Medical Branch (UTMB) that support and further extend these findings were posted on the preprint server bioRxiv. Sera taken 1-month following a third dose showed a 22-fold increase in neutralization titers against Omicron compared to titers just prior to the third dose (7.9 to 8.8 months after second dose), suggesting more robust protection against the new variant may be achieved with the current COVID-19 vaccine series plus a booster dose. Additionally, the neutralizing titer levels against Omicron after immunization with three doses were similar to antibody titer levels after two doses against wild-type and other variants that emerged before Omicron. Further, from 1 to 4 months after a third dose, neutralization titers against wild-type and Omicron decreased by 1.6 and 2.0 times, respectively, suggesting similar waning for both variants. All sera effectively neutralized Omicron at 4 months following a third dose.
Pfizer and BioNTech have put into place a robust booster research program to help ensure that the vaccine continues to offer a high degree of protection. Moving forward, the companies will be evaluating the immunogenicity and efficacy of an additional dose of both the current formulation and an Omicron based vaccine in the clinical setting. The companies have previously announced that they expect to produce four billion doses of the Pfizer-BioNTech COVID-19 Vaccine in 2022, and this capacity is not expected to change if an adapted vaccine is required.
About the Pfizer-BioNTech Laboratory Study
To evaluate the effectiveness of BNT162b2 against the Omicron variant, Pfizer and BioNTech immediately tested a panel of 51 human immune sera obtained from the blood of individuals that received two or three 30-µg doses of the current Pfizer-BioNTech COVID-19 Vaccine, using a pseudovirus neutralization test (pVNT). Each serum was tested simultaneously for its neutralizing antibody titer against pseudovirus bearing the wild-type SARS-CoV-2 spike protein as well as the Beta, Delta and Omicron spike variant. The third dose significantly increased the neutralizing antibody titers against the Omicron pseudovirus by 23-fold. Neutralization against the Omicron pseudovirus after three doses of BNT162b2 was comparable to the neutralization against the wild-type SARS-CoV-2 pseudovirus observed in sera from individuals who received two doses of the companies' COVID-19 vaccine. The geometric mean titer (GMT) of neutralizing antibodies against the Omicron pseudovirus measured in the samples was 164 (after three doses), compared to 413 against the Delta pseudovirus (after three doses) and 160 against the ancestral strain (after two doses). The requirement of a third dose to effectively neutralize Omicron was confirmed using a replicatin...
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