What does Pfizer’s latest data say about its updated vaccine to Omicron 4 and 5?
According to a recent study, Pfizer's bivalent vaccine booster adapted to Omicron 4 and 5 stimulates a much higher immune response than the original vaccine, but there are also those who argue that this may not have to do with efficacy. …
The Pfizer / BioNTech bivalent vaccine booster produces neutralizing antibody titers in adults over 55 about 4 times higher against Omicron subvariants 4 and 5 than the 'old' vaccine based only on the original virus strain.
This was stated by the US pharmaceutical company in announcing the data last Friday, although the drug had already been authorized by both the Food and Drug Administration (Fda) and the European Medicines Agency (Ema).
WHAT THE EMA DECISION WAS BASED ON
At the time of approval by the European Medicines Agency (EMA) of Pfizer / BioNTech's bivalent vaccine upgraded to Omicron 4 and 5, no clinical trial data was yet available.
Therefore, the recommendation was based on data from the bivalent vaccine updated to Omicron 1 and immunogenicity data (i.e. the ability of the vaccine to trigger an immune response) from laboratory (pre-clinical) studies with Comirnaty Original / Omicron BA. 4-5.
Regarding safety, it was instead expected to be "comparable to that of Comirnaty Original / Omicron BA.1 and Comirnaty itself, for which numerous data are available".
THE DATA ON THE BOOSTER WITH THE PFIZER BIVALENT VACCINE
The bivalent booster with the Pfizer / BioNTech vaccine adapted to Omicron 4 and 5, ie containing both the original strain of the virus and that of the most recent variant most widespread worldwide, "generated titers of neutralizing antibodies about 4 times higher against the sub-variants Omicron BA.4 / BA.5 compared to the original Covid vaccine in subjects over the age of 55 ”, reads the press release.
I STUDY
The data is the result of a Phase 2/3 clinical study. According to the note released by the pharmaceutical companies, one month after the administration of the bivalent vaccine as a booster, in adults over the age of 55, the titers of the neutralizing antibodies Omicron BA.4 / BA.5 increased by 13.2 times compared to levels prior to the recall.
While in adults aged between 18 and 55 they increased by 9.5 times.
Over 55s who were given the 'old' vaccine as a booster the recorded increase was only 2.9.
These results, the release points out, reinforce the previously reported early clinical data, measured 7 days after a booster dose of the bivalent vaccine, as well as preclinical data.
WHO CAN RECEIVE IT
For now, Pfizer / BioNTech's bivalent vaccine has been authorized as a booster by the FDA from 5 years of age and by Ema for children aged 12 and over.
SATISFACTION FOR BOURLA
“As we move into the holiday season, we hope this updated data will encourage people to apply for a bivalent booster as soon as they qualify, in order to maintain high levels of protection against the Omicron BA.4 and BA.5 subtypes widely. circulating, ”said Albert Bourla, president and CEO of Pfizer.
"These updated data – he added – also give confidence in the adaptability of our mRNA platform and in our ability to rapidly update the vaccine to adapt it to the most common strains in each season".
POLEMICS
But not everyone is satisfied or reassured by the announced results. "These data do not say whether this (fourfold) increase is clinically significant or not," commented Dr. Paul Offit, director of the vaccine education center at Philadelphia Children's Hospital.
Indeed, some experts warn that antibody values do not directly translate into protective immunity levels and may not necessarily reflect the efficacy of the booster.
This is a machine translation from Italian language of a post published on Start Magazine at the URL https://www.startmag.it/sanita/cosa-dicono-gli-ultimi-dati-di-pfizer-sul-suo-vaccino-aggiornato-a-omicron-4-e-5/ on Mon, 07 Nov 2022 10:52:17 +0000.