Omicron, the newest COVID-19 variant, reduces the effect of the antibodies created by the Pfizer-BioNTech vaccine by almost 40 per cent, found a study by Alex Sigal, who runs the Sigal lab in Durban which is a part of Africa's Health Research Institute.
Even though the study says that the variant decreases the role of the antibodies, the effect of the variant on the immunity induced by T-cells in the body is still to be understood.
The researchers also highlighted that those who had been infected by the SARS-CoV-2 virus and had received at least two vaccine doses were less affected by the Omicron variant. They also found that just like the other variants and the original strain, Omicron uses the ACE2 receptor to bind to cells.
How Did They Conduct The Study?
Sigal's lab took 14 plasma samples from 12 participants of which six were prior infected by Covid-19 while the other six were not. The six infected participants were diagnosed with the D614G mutation strain during the first wave of infections in South Africa in 2020.
All the participants had received the Pfizer-BioNTech COVID-19 vaccine.
What Did They Find?
The virus escaped the neutralising antibodies induced by the vaccine. Neutralising antibodies are the first immune response expressed by the vaccines. They limit the replication and multiplication of the pathogenic virus. In this case, the antibodies formed by the Pfizer vaccine could not stop the virus from actively duplicating.
The researchers found that the geometric mean titer- a measurement of the approximate number of neutralising antibodies created due to the vaccine- stood at 1321 against the D614G strain. This titer fell to 32 against Omicron showing a 41-fold decline in the number of neutralising antibodies that can stop the variant from replicating.
While the variant does manage to escape the neutralising effect of the Pfizer vaccine, the scientists shared that it does not completely escape immunity. For people who were vaccinated and priorly infected, the approximate number of neutralising antibodies were higher, thereby reducing the variant's severity.
The authors of the study believe that vaccination does stop the variant from being more severe.
They also added that an infected and vaccinated person is more likely to not be affected by the new Omicron variant.
Other Therapies For Omicron
Pharmaceutical GlaxoSmithKline shared that their antibody therapy prepared with Vir Biotechnology is working against the Omicron variant, Sotrovimab, the antibody, latches on to the spike protein of even the Omicron variant which has highest mutation in that region.
On the vaccine front, Pfizer-BioNTech have shared that they expect to have a specific vaccine targetting the Omicron variant by March, 2022. Currently, several countries have started giving booster shots of this mRNA vaccine to recipients in order to increase immunity against the virus.