Pfizer and BioNTech informed today thtat they have seen encouraging data in the ongoing booster trial of a third dose of the current BNT162b2 vaccine.
Both companies assure that initial data from the study demonstrate that a booster dose given 6 months after the second dose has a consistent tolerability profile while eliciting high neutralization titers against the wild type and the Beta variant, which are 5 to 10 times higher than after two primary doses.
The pharma multinationals plan to submit the data to the FDA, EMA and other regulatory authorities in the coming weeks.
Clinical studies for an updated vaccine against Delta variant, to start off in August
While Pfizer and BioNTech believe a third dose of BNT162b2 has the potential to preserve the highest levels of protective efficacy against all currently known variants including Delta, the companies are remaining vigilant and are developing an updated version of the Pfizer-BioNTech COVID-19 vaccine that targets the full spike protein of the Delta variant.
The first batch of the mRNA for the trial has already been manufactured. The Companies anticipate the clinical studies to begin in August, subject to regulatory approvals.
The communication also points that data from a recent Nature paper demonstrate that immune sera obtained shortly after dose 2 of the primary two dose series of
BNT162b2 have strong neutralization titers against the Delta variant (B.1.617.2 lineage) in laboratory tests. And both companies also anticipate that a third dose will boost those antibody titers even higher, similar to how the third dose performs for the Beta variant (B.1.351). Pfizer and BioNTech are conducting preclinical and clinical tests to confirm this hypothesis.
Two doses of the current version not enough protective after sixth months
As seen in real world data released from the Israel Ministry of Health, vaccine efficacy in preventing both infection and symptomatic disease has declined six months post-vaccination, although efficacy in preventing serious illnesses remains high.
Additionally, during this period the Delta variant is becoming the dominant in Israel as well as many other countries. These findings are consistent with an ongoing analysis from the Companies’ Phase 3 study.
That is why the companies believe that it is likely, based on the totality of the data they have to date, that a third dose may be needed within 6 to 12 months after full vaccination.
While protection against severe disease remained high across the full 6 months, a decline in efficacy against symptomatic disease over time and the continued emergence of variants are expected. Based on the totality of the data they have to date, Pfizer and BioNTech believe that a third dose may be beneficial to maintain the highest levels of protection.