By Pamela Cruz. Peninsula 360 Press [P360P].
The pharmaceutical company Pfizer and the German biotechnology company BioNTech announced Wednesday that, according to an initial laboratory study, a third dose of its COVID-19 vaccine increases neutralizing antibodies and is effective against the Omicron variant, similar to that obtained by the first doses with respect to the previous variants.
"Stronger protection can be achieved with a third dose, as data from additional company studies indicate that a booster with Pfizer and BioNTech's current COVID-19 vaccine increases antibody titers by 25-fold," details the document issued Dec. 8.
According to preliminary data from the companies, a third dose provides a similar level of neutralizing antibodies to Omicron as observed after two doses against the original type and other variants.
The study notes that a third dose also strongly increases the number of immune system cells against multiple antigenic determinants - epitopes - of spike proteins that are thought to correlate with protection against serious diseases.
Compared to the original virus, the vast majority of these epitopes remain unchanged in the Omicron spike variant, the study notes.
"While two doses of vaccine can offer protection against severe disease caused by the Omicron strain, it is clear from these preliminary data that protection is enhanced with a third dose of our vaccine," said Albert Bourla, Pfizer's president and chief executive officer.
He stressed that ensuring that as many people as possible are fully vaccinated with the first two series of doses and a booster is still the best course of action to prevent the spread of COVID-19.
For his part, Ugur Sahin, MD, CEO and co-founder of BioNTech, noted that the first set of preliminary data indicates that a third dose could still offer a sufficient level of protection against diseases of any severity caused by the Omicron variant.
"Broad vaccination and booster campaigns around the world could help us better protect people everywhere and get us through the winter season. We continue to work on a tailored vaccine that we believe will help induce a high level of protection against Omicron-induced COVID-19 disease, as well as prolonged protection compared to the current vaccine," he said.
While these results are preliminary, the companies said they will continue to collect more lab data and evaluate real-world effectiveness to assess and confirm protection against Omicron and will report on the most effective path forward.
On November 25, the companies reported that they have begun development of an Omicron-specific COVID-19 vaccine, and that development will continue as planned in the event that adaptation is needed to increase the level and duration of protection against this variant.
They added that they can produce the first batches of the Omicron-based vaccine and expect them to be ready for shipment within 100 days, pending regulatory approval.
Pfizer and BioNTech have also tested other variant-specific vaccines, which have produced very strong neutralisation titres and a tolerable safety profile, they said, and based on that experience, they were confident that, if needed, they can deliver an Omicron-based vaccine in March 2022.
The companies have also previously initiated clinical trials with variant-specific vaccines (Alpha, Beta, Delta and Alpha/Delta Mix) and data from these studies will be submitted to regulatory agencies around the world to help accelerate the vaccine adaptation process and obtain regulatory clearance or approval of an Omicron-specific vaccine, if necessary.
The companies have previously announced that they expect to produce four billion doses of their COVID-19 vaccine by 2022, and this capacity is not expected to change if a tailored vaccine (Alpha/Delta Mix) is required.
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