The Pfizer vaccine is moving towards the green light for the third dose in the USA. After the delivery of the first data, Pfizer and BioNTech today announce that they have initiated the application for an additional biological license for the approval by the US Food and Drug Administration (Fda) of a third booster dose of the Covid Comirnaty vaccine * to prevent Covid in people aged 16 and over. The companies also communicate that they intend to complete the presentation of the material by the end of this week and reiterate that they intend to also submit the data to the European Medicines Agency Ema and other regulatory authorities in the coming weeks (in addition to submitting the results studies to a peer-reviewed journal).
The dossier submitted to the FDA includes data from a Phase 3 clinical study of 306 participants aged 18 to 55 who received a booster dose (third dose) of the vaccine between 4.8 and 8 months after completing the two-dose primary regimen, with a mean follow-up time of 2.6 months after booster. The third dose elicited, according to the two companies in a note, “robust neutralizing antibodies against the original (wild-type) strain of the virus”. One month after this booster, the levels were “3.3 times” those seen one month after the second dose. Furthermore, “99.5% of the participants had a quadruple response after the third dose, compared to 98% after the second dose”.
The reactogenicity profile within 7 days after the third dose was generally mild to moderate. The most common events included injection site pain, fatigue, headache, muscle and joint pain, and chills. “The frequency of any serious systemic event after the booster dose was low – add Pfizer and BioNTech – And the frequency of reactogenicity was similar or better than the second dose of the primary series”.
A third dose of this vaccine is not currently licensed for wide use in the United States but, under the current modified emergency use authorization, it was licensed on August 12 for people aged 12 and over who have undergone a transplant. or who have been diagnosed with a condition believed to have an equivalent level of immunocompromise.