⬇️ TL;DR:
IN A LAB DISH (so NOT in real life), antibodies from vaccinated individuals (two doses of Pfizer-BioNTech), were significantly less effective at neutralizing Omicron compared to the original variant—about a 20-40-fold reduction in neutralization.
While this is substantially more loss of neutralization than previous variants…this does NOT tell us how well the vaccines will protect against Omicron in real life.
💥Neutralization is NOT the same as vaccine effectiveness.
➡️ Neutralizing antibodies are important for initial infection, less important for prevention of severe disease.
➡️ Other facets of the immune response such as T-cells and cell-mediated immunity were not measured and are more robust to variants.
➡️ There can be “head room” in antibody levels– if we have more than needed, a reduction in doesn’t matter as much.
IMPORTANTLY– this loss of neutralizing ability was much less for people with two doses of vaccine AND a previous infection (HYBRID immunity–green lines in figure), suggesting 3 doses may also keep us above that threshold of protection.
⚠️ Caveats: These data were from 12 individuals, and the authors state these data are still preliminary results subject to further refinements. Still very early days of this science.
Also released today, another study by Swedish researchers with different methodology (using pseudoviruses rather than live virus), has shown loss of neutralization from Omicron that is less severe than the South Africa study-potentially good news.
We’ve had somewhat concerning neutralization lab results from previous variants such as Beta and Gamma that didn’t prove as nasty in real life. So, there will still no substitute for time to understand the implications of Omicron for the real world.
⬇️ BOTTOM LINE:
For all the mutations identified on the Omicron variant, things could have been worse. Early signs suggest capacity for partial immune evasion which may cause more “breakthrough” or re-infections, but 3 doses of vaccine are likely to hold up well.
A quote from the study author:
“Just be be clear… this was better than I expected of Omicron. The fact that it still needs the ACE2 receptor and that escape is incomplete means its a tractable problem with the tools we’ve got.”
Love,
Those Nerdy Girls
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