Omicron variant: is the Pfizer vaccine effective with 3 doses?
THE OMICRON VARIANT. according to Pfizer’s first data, three doses of its vaccine would neutralize the Omicron variant while two doses would be much less effective. This new variant, more contagious than the Delta variant, is not considered more dangerous for the moment.
The first case of the Omicron variant was reported in South Africa on November 24, 2021. On December 5, Santé Publique France confirmed 25 cases of infection by this variant in France, including “21 imported cases,” said Health Minister Olivier Véran during a press briefing on December 6.
“Omicron is very contagious, even more, contagious than the Delta variant,” but there is no clinical evidence that it is more dangerous, the minister added. Concerning the effectiveness of the vaccines, the first data are gradually coming in. On December 8, the Pfizer laboratory informed in a press release that three doses of its anti-Covid vaccine “neutralize the Omicron variant while two doses show considerably reduced neutralization titers”.
With two doses, vaccinated individuals still appear to be protected from severe forms. With a third dose, “neutralizing antibody titers increase 25-fold compared to two doses. Pfizer-BioNTech continues to make progress on the development of a vaccine specific to the Omicron variant and expects it to be available by March.
The Omicron variant has a high number of mutations (32 on the spike protein), more than Delta and its predecessors, making it difficult for scientists to target all of these mutations with available vaccines.
As for symptoms, a doctor in South Africa who witnessed the first cases of the Omicron variant reported to the BBC “very very mild” signs.
The first patient “had a bit of a headache, he didn’t really have a sore throat, no cough, no loss of taste or smell”. His symptoms were “very, very mild”.
France has tightened its entry requirements since December 4 by placing certain countries on the “scarlet” list. From now on, unvaccinated travellers from the EU must have a test less than 24 hours old to come to France. Outside the European Union, everyone needs a test less than 48 hours old. Definition, specific symptoms of covid, vaccine… All about the Omicron variant.