The Pfizer covid-19 vaccine offers low immunity against the newfound variant of coronavirus – Omicron as compared to other variants, and as per the lab study, a booster shot may be a good protection option against Omicron.
However, the study is yet to be peer-reviewed, but the post on preprint repository medRxiv recently also concluded that some immunity is offered by people who were double vaccinated and infected previously.
The advent of the new variant, Omicron, has significantly raised the health concerns that this variant can have. However, on the basis of a number of mutations in the spike protein, this variant can escape from vaccine-elicited immunity.
The rapid spread of this new variant in South Africa has significantly shaken the authorities with the fresh wave of cases and new hospitalizations. Also, the World Health Organization has warned the world against the new variant omicron, indicating it may fuel severe consequences that can lead covid-19 infection more transmissible.
The SARS-CoV-2 virus utilizes the spike protein to infect and enter the human body.
“The clinical implications of these important laboratory data need to be determined. It is likely that lesser vaccine-induced protection against infection and disease would be the result,” said Professor Willem Hanekom, Executive Director, Africa Health Research Institute, South Africa.
“Importantly, most vaccinologists agree that the current vaccines will still protect against severe disease and death in the face of Omicron infection. It is, therefore, critical that everyone should be vaccinated,” Hanekom said in a statement.
Furthermore, researchers examined whether or not Omicron can escape antibody neutralization initiated by the Pfizer mRNA vaccine. Also, they investigated if the virus needs binding to ACE2 receptors on the human cell to infect them. They take advantage of human lung cell line copy designed to express ACE2 receptors to both test neutralization and isolate the virus. The test results also highlight that ACE2 is needed for entry.
The researchers also investigated the efficiency of Plasma from the participants of the Pfizer vaccinated study to neutralize Omicron against the ancestral D614G virus. They further examined 14 plasma samples from 12 participants, of which 6 have no history of previous covid infection nor detectable antibodies indicator of the previous infection.
The remaining 6 participants further reveal the record of previous infections in the first SARS-CoV-2 infection wave in the South Africa region, where it was with the ancestral D614G variant.
Such samples hold a very strong neutralization for the D614G variant in line with sampling after vaccination as per the study.
However, the neutralization from vaccines for Omicron indicated a 41-fold decline.
5 participants who hold the historical record of infection highlighted the relative high neutralization titers with Omicron, the researchers said.
In addition, the researchers also concluded that around three-fold reduction was reported for the beta variant immune escape from Pfizer.
“The results we present herewith Omicron show much more extensive escape,” they added.