Pfizer news - booster neutralizes Omicron variant!
2 doses had significantly reduced ability to neutralize; however the vaccine likely still protects against severe disease and death
In a press release today, Pfizer released some encouraging preliminary data from their studies on the vaccine against Omicron. I’m waiting for them to release their data, but this is exciting..
They took samples from people vaccinated with 2 doses only, or those with 2 doses and then a booster, and compared the ability of the antibodies in the samples to neutralize the Omicron variant.
They found that 2 doses of their mRNA vaccine had about a 25-fold reduction in neutralization against Omicron compared to the original strain. However, 3 doses (2 dose + booster) were able to completely neutralize the variant. The 3rd dose was as good as 2 doses against the original strain.
This is good news - it indicates that the boost provided by 3 doses may be good enough to protect against infection from the Omicron variant.
A third dose also increases T-cell levels, and this is against multiple different parts (epitopes) on the spike protein.
Remember, this is only against infection, which is what antibodies are initially involved with. Our immune systems are complex, and these studies only look at one aspect of it (antibodies). The immune response from the vaccine is complex and provides multiple levels of protection, such as T-cell immunity that plays a major role in protecting against severe disease and death. Also, the immune response recognizes many different parts of the virus and spike protein - so even if there are mutations, it is very unlikely that the body wouldn’t recognize the virus at all
We know this because the vaccine induced T-cell response also recognizes a lot of different epitopes of the spike protein, even with all of Omicron’s mutations. So vaccinated people infected with Omicron are likely still protected from severe disease and death; even with just 2 doses.
What does this mean?
This early data supports the value of being vaccinated PLUS getting your booster shot. I would wager that Moderna has similar results, as both are mRNA vaccines. If you are not fully vaccinated, please get fully vaccinated, and then also get your booster for optimal protection. You can get either Moderna or Pfizer as your booster shot. We don’t have data on JnJ against Omicron yet.
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Dr. Siyab
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