Coronavírus: Pfizer announces that its third dose is effective against a micron after a preliminary study | Science

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A preliminary study by the companies Pfizer and BioNTech indicates that a third dose of reinforcement of their vaccine against covid-19 increases neutralizing antibodies by up to 25 times and is effective against the micron variant. According to the pharmaceuticals, the degree of protection as a reinforcement is similar to that provided by the first doses against the initial variants, as the duplication scheme is less effective in the face of the emergence of the new coronavirus lineage. The Pfizer vaccine is most widely used in Europe and is also a preferential immunizer in Brazil for application as a booster dose.

Both companies have announced that they are developing a specific vaccine against ômicron, scheduled for March, their studies show that the current and effective immunizer is complemented with a third dose. In contrast, according to pharmaceuticals, two doses were geram niveis of neutralizing antibodies “significantly reduced”. A Pfizer affirmed that the double dose scheme “may not be sufficient to protect against infection with the micron variant”, emphasizing: “A more robust protection can be obtained with a third dose”.

Both doses of the vaccine can still offer protection against serious harm caused by microns, it is clear that protection is better with a third dose of our vaccine

Albert Bourla, Chairman and CEO of Pfizer

Isso não means that those vacinated with two doses are unprotected against the ômicron variant. Albert Bourla, President and CEO of Pfizer, explains: “Even if we do two vaccines we can still offer protection against serious harm caused by microns, it is clear, based on preliminary data, that the protection is better than a third dose of vaccine. ”. Bourla proposes to advance the maximum possível in vacinação with the double scheme and begin to administer or reinforce.

Ugur Sahin, co-founder and executive director of BioNTech, adds that “extensive vaccination and reinforcement campaigns around the world could help to better protect people in all places and overcome the winter season”, which begins every two weeks in the Hemisphere North. Sahin says that the company has been working since November 25 with a new generation of vaccination, which will increase the duration of immunity and protection against severe disease and against the micron variant. If the approval processes will run as expected, this new vaccine would be available on the market within 100 days, by March of next year.

The tests against the omicron foram variant were tested with serum samples of immunized people between three and four weeks after receiving the second dose from Pfizer. Each serum was tested simultaneously to determine the level of neutralizing antibodies generated against the protein. spike of the SARS-CoV-2 virus (also used by the coronavirus to enter human cells) both in its first variants and in its recently sequenced micron.


The scientific community reacted with caution to the results of the Pfizer study, reiterating that the two-dose scheme provides protection and asserting that the reinforcement dose is timely, as established in a recent study on its safety and efficacy, which varies according to as combinations of vaccines.

Nesse sense, Paul Moss, Professor of Hematology at the University of Birmingham, affirmed ao Science Media Center: “These discoveries are important, but they can be interpreted in different ways: the worrying thing is that the neutralization of antibodies is about 40 times reduced against ômicron in comparison with the original virus from Wuhan. This means that only 2.5% of the antibody neutralization activity is maintained. On the positive side, the virus has not evolved apart from the use of the ACE2 receptor to enter the cells and, therefore, the antibodies that form to block this interaction are not totally ineffective. Além said, emerging evidence on booster vaccines shows that they are capable of generating very high levels of antibodies that should potentially provide valuable protection against infection, and cellular immune responses should also remain largely intact. ”.

The virus did not evolve apart from the use of the ACE2 receptor to enter the cells and, therefore, the antibodies that form to block this interaction are not totally ineffective.

Paul Moss, Professor of Hematology at the University of Birmingham

For Daniel Altmann, professor of immunology at Imperial College London, the results of the study are a “still stronger argument for obtaining more extensive and faster possible reinforcements.”

Molecular virology professor Jonathan Ball insists on the self-defense capacity acquired by the body as a duplicate: “A reduced antibody immunity could mean that more people could be infected and have mild symptoms, I still trust that as you vaccinate, especially after a reinforcing, protecting from serious forms da doença”.

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