The Pfizer / BioNTech vaccine is effective against covid-19 variants originating in the UK and South Africa. This is the result of a study published this Monday in Nature Medicine , which showed better results in the first case, the British variant (called B.1.1.7), than in the second, the South African, or B.1.351. The differences, however, are small.

The study used samples of genetically engineered viruses to look similar to the variants, and used them in the blood of people who were inoculated with the Pfizer vaccine. And the most important conclusion is that the antibodies that were in the blood of the vaccinees responded effectively .

The authors engineered three severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viruses containing key spike mutations from the newly emerged United Kingdom (UK) and South
African (SA) variants: N501Y from UK and SA; 69/70-deletion

N501Y + D614G from UK; and E484K + N501Y + D614G
from SA.

Neutralization geometric mean titers (GMTs) of 20 BTN162b2 vaccine-elicited human sera against the three mutant viruses were 0.81- to 1.46-fold of the GMTs against parental virus, indicating small effects of these mutations on neutralization by sera elicited by two BNT162b2 doses.

Another important fact to take into account is that the study was peer-reviewed, although it has the limitation that “ the modified viruses [as was the case] do not include all the mutations found in the variants ”, according to the researchers, cited in the presentation of the study, which had been pre-presented at the end of January .

The news is, nevertheless, encouraging, especially if we think that this Sunday South Africa temporarily suspended the vaccination program in the country after a study demonstrated a “limited” effectiveness of the AstraZeneca / Oxford vaccine against variant B.1.351.