New study shows that third dose of Pfizer increases antibodies against omicron

A new study evaluating the efficacy of Pfizer-BioNTech’s COVID-19 vaccine against the omicron variant indicates that three doses could offer “a sufficient level of protection” against the disease.

The SARS-CoV-2 omicron (B.1.1.529) that circulates throughout the world is highly transmissible because it has accumulated a very high number, higher than other times, of mutations, especially in the spike protein, which the virus uses to enter the human cell and the common target, with different technologies, of current vaccines.

This implies that recognition by neutralizing antibodies is compromised.

In a study published in the journal Science, researchers from both pharmaceutical companies led by Alexander Muik analyzed the Wuhan (native) pseudovirus and the beta, delta and omicron variants in sera from 51 participants who received two or three doses of the COVID vaccine. -19 based on messenger RNA.

After two doses, the sera had more than 22-fold reduced neutralizing titers against omicron compared to the original Wuhan virus.

One month after the third dose of the preparation, the neutralization titers against omicron increased 23-fold compared to the two doses, with neutralization titers similar to the original Wuhan coronavirus after two doses.

The data suggest that a third dose of this vaccine enhances antibody-based immunity against omicron, consistent with previous observations that the third vaccination amplifies humoral immune responses against variants of concern, the authors write.

“More real-world and clinical trial data will soon emerge to address the efficacy of a third dose against COVID-19 mediated by the omicron variant,” they conclude.