Pfizer and its partner BioNTech on Thursday said that they have begun to test how well the third dose of their authorised vaccine stacks up against new coronavirus variants.
The study will evaluate up to 144 Phase 1 participants in two age cohorts, 18-55 and 65-85 years of age.
The study will include trial participants who received the two doses in the Phase 1 study 6 to 12 months ago in order to assess the boostability of BNT162b2 (the vaccine), the companies said. It will also involve testing how well their antibodies are able to neutralize "strains of interest" in the lab, the companies said.
The outlet reported that volunteers would receive a third dose between 6 and 12 months after their earlier two doses. The dosage would be identical to what's currently authorised, 30 micrograms.
"While we have not seen any evidence that the circulating variants result in a loss of the protection provided by our vaccine, we are taking multiple steps to act decisively and be ready in case a strain becomes resistant to the protection afforded by the vaccine. This booster study is critical to understanding the safety of a third dose and immunity against circulating strains," said Albert Bourla, Chairman and Chief Executive Officer, Pfizer.
He added, "At the same time, we are making the right investments and engaging in the appropriate conversations with regulators to help position us to potentially develop and seek authorization for an updated mRNA vaccine or booster if needed."
However, Bourla noted the companies haven't yet seen compelling evidence that variants are resistant to its vaccine, though they are taking steps to be prepared.
Ugur Sahin, CEO and Co-founder of BioNTech, said, "Our proactive clinical development strategy aims to create the foundation today, that will enable us to address the challenges of tomorrow. We want to be prepared for different scenarios."
The Pfizer-BioNTech COVID-19 vaccine is authorised for use under an Emergency Use Authorization (EUA) for active immunization to prevent coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in individuals 16 years of age and older.
CNN further reported Pfizer and BioNTech are also "in ongoing discussions with regulatory authorities" about potentially testing a vaccine has been modified to protect against concerning variants in a Phase 1/2 study.
On Monday, the US Food and Drug Administration (FDA) announced new guidelines that would streamline and quicken the process of updating vaccines to target variants. An agency official estimated this could involve several hundred individuals and take a few months.