The first batch of preliminary laboratory data on the Omicron coronavirus virus has emerged, and the result has largely left health experts predictable: The protective antibodies from two doses of the Pfizer-BioNtech vaccine are significantly less effective at thwarting the newer version than the old one. . Virus version. However, after a booster dose the antibody ability appears to rebound to fight Omicron.
The results suggest that people who have had only two doses of the mRNA vaccine may not be protected from infection, but they will be protected against severe disease. The findings also suggest that a booster dose of current vaccines will be needed to maintain a high level of protection against Omicron—or even an Omicron-specific shot in the future.
The top-line findings and conclusions come from three different sets of laboratory experiments—all of which are extremely preliminary, involve small sample numbers, and have not been peer-reviewed or published in scientific journals.
Pfizer and BioNTech Data
The most recent data comes from Preliminary results were reported online Wednesday morning by Pfizer and BioNTech, The companies conducted laboratory experiments in which antibodies were injected from the blood serum of people vaccinated against a pseudovirus engineered to mimic the Omicron variant. The experiments specifically measured the activity of neutralizing antibodies, which are a subset of antibodies that can bind to SARS-CoV-2 virus particles in a way that prevents the virus from entering human cells. Passive antibodies are most powerful at preventing infection, but the immune system also produces a diverse array of other antibodies that can help fight infection. Additionally, protective cell-based responses occur in the immune system that are not captured in these types of laboratory experiments.
In experiments using blood sera from people fully vaccinated with the Pfizer-BioNTech vaccine (two doses), neutralizing antibody levels compared to levels seen against a pseudovirus mimicking an older version of the virus. 25 times lower than that of Pseudovirus. But when the companies looked at the blood sera of fully vaccinated people a month after receiving the vaccine booster shot (three doses), levels of neutralizing antibodies against Omicron increased 25-fold, giving them a chronic exposure to the virus. Neutralizing antibody levels observed against the volumes were made comparable. ,
Albert Bourla, CEO of Pfizer, said in a statement, “While two doses of the vaccine may still provide protection against severe disease caused by the Omicron strain, it is clear from these preliminary data that the third dose of our vaccine provides protection against improves.” “Ensuring that as many people as possible are fully vaccinated with the first two-dose series and a booster is the best course of action to stop the spread of COVID-19.”
The companies also reported that they are still working on an Omicron-specific vaccine dose, if needed. The companies said the deadline for the first batch to become available is within 100 days from now.